Table of Contents

1. Top of Page

2. Tode-RC $33.57

2.1 Keypad Assembly PCB.231Q $4.94

2.1.1 Materials

A. Parts $3.25

B. Supplies $1.34

C. 3D-Prints $0.35

2.1.2 Schematic& Layout

2.1.3 PCB Assembly

A. Push buttons

B. Pin Header

C. LED

2.1.4 Keypad Case

A. Heated Nuts Insert

B. Face Decals (Optional)

C. Fasten

2.2 Arduino Assembly $12.76

2.2.1 Materials

A. Parts $12.37

B. Supplies $0.20

C. 3D Prints $0.39

2.2.2 Arduino Shell

A. Arduino Mega-Pro in Plastic Shell

2.3 Ebyte-RF Assembly PCB.BD241S $15.87

2.3.1 Materials

A. Parts $14.44

B. Supplies $1.06

C. 3D-Prints $0.37

2.3.2 Schematic & Layout

2.3.3 Radio-PCB Assembly

A. Resistors

B. Arduino Sockets

C. Radio

D. CN3903 Power Supply

E. DC Barrel Jacks

F. Keypad-Display Plug

2.3.4 Radio Casing

2.4 Final Assembly $1.23

2.4.1 Materials

A. Supplies $1.23

2.4.2 Diagram

2.4.3 Casing Assembly

A. Radio Foil

B. Back-side Fasteners

C. Display Fasteners

D. Antenna

3. Battery-Tray Option $3.00

3.1 Materials

A. Supplies $2.06

B. 3D-Prints $0.94

3.1.2 Assembly

4. BIOPH Option $4.49

4.1.1 Materials $3.67

A. Parts $0.93

B. Supplies $1.14

C. 3D-Prints $0.78

4.1.2 DIN-Mount Materials $0.82

A. Parts $0.66

B. Supplies $0.16

4.1.3 Diagram

4.1.4 Assembly

A. Sockets in Front-Side

B. Front-Side on PCB

C. Pin Headers

D. Solder Pin Header Array

E. Attach Back-Side

F. (OPTION) Screw on DIN Brackets

( 4.1.4 BIOPH Option $4.49 :: BIOPH Option $4.49 :: Assembly ) Page -26-


Tode-RC .BD241S

Hardware Development

Arduino-Mega UI + Ebyte T20/30db RF



by TGit-Tech [ http://www.TGit-Tech.com ]

Tode-RC Model# BD241S / Last Updated: 2025-01-12






1.Table of Contents



2.Tode-RC $33.57

2.1Keypad Assembly PCB.231Q $4.94

2.1.1Materials

A.Parts $3.25

  • 1.8 or 1.77 -Inch TFT LCD Display

    • Power-In: 5Vdc

    • Resolutions: 128 x 160dpi ST7735 RGB

    • Dimensions: 35mm x 56mm

    • Temp: -20C to 70C

    • (8)Pin-Order: GND,VCC,SCL,SDA,RES,DC,CS,BL

    • Pricing: $3.00/each (~4.38 to 2.64)

  • Digital Keypad PCB version 231Q

    • Manufacturer: jlcpcb.com

    • Pricing Each: $0.25

    • Batch Price: $20.93 per 100

    • Zip Folder: JLCPCB-231Q-output


B.Supplies $1.34

(1) 1x8P Male Pin Header

PCB-J1, Dupont 2.54mm-Pitch

Cut from 40-Pin Male Pin Header

$0.01/pin = $0.08

(6) 6x6-7mm Push Buttons

PCB-SW(1-6)

DIP-4 Tacticle Through-Hole

$0.15/ea = $0.90

(1) 47K 0805 SMT Resistors

PCB-R7

$0.01/ea = $0.01

(1) 3mm Green LED

PCB-D1

$0.05/ea = $0.05



(2) M2x0.4-8 Flat Phillips

Machine Screw & Nut

Display & Keypad to Cover

$0.10/pair = $0.20


(1) M2x0.04–20mm Machine Screw

Used as Heating stem ONLY

$0.10/ea = $0.10


C.3D-Prints $0.35


Tode-DispKB-3DShell.stl

Folder: .\Tode-RC\BD241S\3DPrints\stl\BD241S.3DDispKB.24CM.stl

Layer Height: 0.2mm

Infill Density: 100%

Supports: OFF

Plastic: 15-grams @ $0.02/g = $0.30

Printer-use: @ $0.0015/g = $0.0225

Power: 2h 29m @ $0.01/hr = $0.0248

TOTAL COST: $0.35


2.1.2Schematic & Layout

SCHEMATIC

LAYOUT


D1 = 3mm Round Green LED

R7 = 47Kohm 0805 SMT Resitor

- 5V/47K = 0.1mA LED current.

SW(1–6) = 6x6x7mm Tactical Switches

2.1.3PCB Assembly


A.Push buttons

  • Push (6) 6x6x7mm Tactile Push buttons into PCB.

  • Solder the push buttons to the PCB



B.Pin Header

  • Cut and Insert a 8P male header

  • Push pins down flush with top

  • Solder back-side of pins



C.LED

  • Solder a 47K-ohm 0805 SMT resistor

  • Insert a 3mm Green LED (do not solder yet)

    • Short-lead in square-pad hole (GND)





2.1.4Keypad Case

A.Heated Nuts Insert

  1. Thread a M2 nut onto just the very end of a long M2 Machine Screw (i.e. M2x0.04-20mm).


  1. Heat the Nut with a heat gun.


  1. Press the heated nut into the plastic as shown aligning the nuts shape with the shape in the casing.


  1. Using a screwdriver, press and drive the screw in, to clear excess plastic out the back-side then unscrew completely.


  1. Repeat for both nut locations under display opening


B.Face Decals (Optional)

  • This step requires a cutting machine and special materials and design files.


  • Contact Tgit-Tech if you'd like to purchase face stickers.

  • DIY hobbyists can skip this step to create a unit without custom face stickers.


C.Fasten

  1. Place TFT display face-down on case first.


  1. Place Keypad with Buttons over the top and align holes.


  1. Fasten with (2) M2x0.4 – 8mm machine screws.


  1. Align LED with hole in casing.


  1. Solder the LED pins and clip excess off.




2.2Arduino Assembly $12.76

2.2.1Materials

A.Parts $12.37

Arduino Mega Pro Mini [ATmega2560]

B.Supplies $0.20

(2) M2.5x0.45 x 8mm Phillips-Flat Machine Screws & Nuts $0.32

Attaches Arduino Mega Pro Mini to 3D Casing

24CM-Pricing: (2) Screws @ $0.08/ea

24CM-Pricing: (2) Nuts @ $0.08/ea


C.3D Prints $0.39



ALL-AMPCenter.stl

Folder: \All-3DPrints\stl


PLA Filament: 17g @ $0.02/g = $0.34

Printer-use: 17g @ $0.0015/g = $0.0255

Power: 2h 23m @ $0.01/hr = $0.025


TOTAL COST: $0.39


2.2.2Arduino Shell

A.Arduino Mega-Pro in Plastic Shell

Fasten the Arduino Mega Pro Mini with Male Pin Headers into the 3D Printed case using (2) M2.5x0.45 – 8mm flat-head machine screws with nuts on Arduino side.


Be sure not to damage components next to the top nut while tightening.


2.3Ebyte-RF Assembly PCB.BD241S $15.87

2.3.1Materials

A.Parts $14.44

(1) BD241S PCB (Back-plane)

  • File Location: \Tode-RC\BD241S\kicad

              \BD241S-Backplane

              \Final_JLCPCB-241S.zip

  • Manufacturer: jlcpcb.com

  • Batch Price: $46.11 per 75

  • Pricing: $0.61/ea = $0.61

(1) CN3903 DC-DC Buck Step-Down Board 5V@3A

  • Voltage: 5Vdc to 30Vdc Input to 5Vdc Output

  • Size: 17.5mm x 12mm x 4.3mm (LWH)

  • Max Output: 3A

  • 24CM-Pricing: (10pcs) $7.99 = $0.80

(1) Ebyte Radio (Various T20D/T30D Options)

        • E22-900T30D Pricing: $10.77/ea

        • E22-400T30D Pricing: $7.94/ea

        • E220-400T30D Pricing: $10.07/ea

        • E32-433T30D Pricing: $9.06/ea

        • E32-433T20D Pricing: $6.44/ea

(1) SMA Aerial Antenna (Various Options)

    • Omni 6cm 2dbi: $1.09/ea

    • Omni-folding 11cm 3dbi: $1.04/ea

    • Omni-folding 19cm 6dbi: $2.26/ea

Estimated Price $2.26/ea

B.Supplies $1.06

(1) 2x7P Pin Socket

Dupont 2.54mm-Pitch

Backplane PCB

$0.18/ea = $0.13



(1) 2x8P LONG-Lead Socket

Dupont 2.54mm-Pitch

Keypad & Display Connect

$0.15/ea = $0.15

(1) 2x4P Pin Socket

Dupont 2.54mm-Pitch

Radio, Buttons & IO

$0.17/ea = $0.17

(1) 1x4P Pin Header

Dupont 2.54mm-Pitch

Radio Ground Stubs

$0.01/pin (from 40-pin cut) = $0.04

(1) 2x3P Pin Socket

Dupont 2.54mm Pitch

ICSP and Power

$0.10/ea = $0.12

(4) 1x1P Pin Header

Dupont 2.54mm-Pitch

Radio Ground Stubs

$0.01/pin (from 40-pin cut) = $0.04

(2) #2-1/4” Screw

PCB to Casing

Phillips-Flat Sheet Metal Screw

$0.10/each = $0.20

(2) 5.5x2.1-9mm DC Barrel Jack PCB

Female PCB Mount

3-Terminal, 9mm Connector Depth.

$0.08/ea = $0.16

(1) 2.2KΩ 0805 SMT Resistor

PCB-R3

$0.01/ea = $0.01

(2) 4.7KΩ 0805 SMT Resistors

PCB-R1 & R2

$0.01/ea = $0.02

(2) 10Ω 0805 SMT Resistors

PCB-R4 & R5

$0.01/ea = $0.02



C.3D-Prints $0.37

BD241S-Backplane.24CM.stl

Folder: \BD241S\3DPrints\stl


PLA Filament: 16g @ $0.02/g = $0.32

Printer Use: 16g @ $0.0015/g = $0.024

Power: 2h 36m @ $0.01/hr = $0.025


TOTAL COST: $0.37

2.3.2Schematic & Layout

    SCHEMATIC

LAYOUT

J1 – Arduino PWR – 2x3P Socket

J2 – Arduino ICSP – 2x3P Socket

J3 – Generic Test-Points

J4 – Ebyte T30D Radio Connections

J5 – DispKB Connections

J6 – PWR Test-Points

J7 – Arduino Radio, Key, TFT Connections

J8 – Input Barrel Jack (7-30Vdc)

J9 – Output Barrel Jack (5Vdc)

J10, J11, J12, J13 – CN3903 Power Supply

J14 – Ebyte T20D Radio Connections

R1,R2 - 4.7KΩ Rx,Tx Resistors

R3 – 2.2KΩ Arduino D13 Pull-up on OK keypad.

R4,R5 – 10Ω Jumpers



2.3.3Radio-PCB Assembly


A.Resistors

Solder Resistors on PCB

  • R1 = 4.7KΩ above Ebyte-J14

  • R2 = 4.7KΩ above Ebyte-J14

  • R3 = 2.2KΩ side of ICSP Bottom

  • R4 = 10Ω side of ICSP Top

  • R5 = 10Ω above Ebyte-J14, Right-side


TEST – using Ω-meter test

- (Rx) YELLOW to YELLOW = 4.7KΩ

- (Tx) GREEN to GREEN = 4.7KΩ

- (M1) BLUE to BLUE = 10Ω

- YELLOW to GREEN = No-Connection


Refer to Shematic & Layout for specifics.



B.Arduino Sockets


  1. Attach Dupont Sockets to Arduino

  • J1 = (1) 2x4P Left-Top Arduino

  • J7 = (1) 2x7P Left & 7-Rows down

  • J2 = (1) 2x3P on Arduino ICSP Header


  1. Place BD241S PCB on Socket Pins.


  1. Solder Dupont Sockets to PCB.


  1. Unplug the PCB from Arduino.

C.Radio

  1. Place Pin Header into Top of PCB.

    1. For T20D radios use 1x3P Header

    2. For T30D radios use 1x4P Header


  1. Place Radio onto PCB.


  1. Solder Radios 7-Pins to PCB.

  2. Solder the 1x3P or 1x4P Pins to PCB.


  1. Trim excess Pin Length from back PCB.

D.CN3903 Power Supply

  1. (4) 1x1P Headers into Bottom of PCB.


  1. Place CN3903 Power Supply Module as pictured with its coil-block facing the PCB screw-hole (fatter-side).


  1. Solder Pins to PCB and Power Supply.

E.DC Barrel Jacks

  1. Solder (1) Barrel Jack (Power-IN) pointing down on skinny-side.


  1. Solder (1) Barrel Jack (IO-Power) pointing to the PCB edge on the fat-side/ screw-hole-side of the PCB.


Component white footprint on PCB can help verify barrel jack direction.



F.Keypad-Display Plug

  1. Plug the AMP-Center into PCB.


  1. Insert 2x8P Long-Leg Female Header into PCB.


  1. Place and align pins of the Keypad-Display to plug into the 2x8P Back-plane Plug.


  1. Use Pinch method and Thumb to press the 2x8P plug into the Keypad-Display.


  1. Align the Assemblies then solder the 2x8P plug to the PCB. Consider screwing the Keypad top-screws to the AMP-Center to help align.


  1. Trim excess lead length from back of PCB.



2.3.4Radio Casing

  1. Unplug PCB and insert into casing putting the radio antenna through the hole first.


  1. Make sure PCB is pressed down against Back-plane casing completely then use (2) #2-1/4 screws to secure.




2.4Final Assembly $1.23

2.4.1Materials

A.Supplies $1.23

(4) #2 x 3/8” Screws

Display to Center

Phillips-Pan Sheet Metal Screw

$0.10/ea = $0.40

Aluminum Foil

Approximately 1/2sqft

$0.06/sqft = $0.03

(4) #2 x 1/2” Screw

Backplane to Center

Phillips-Flat Sheet Metal Screw

Sheet Metal Screw

Price $0.06/ea = $0.24



2-Inch Clear Packing Tape

Aluminum Foil Insulation


2.4.2Diagram




2.4.3Casing Assembly

A.Radio Foil

  1. Cut a rectangle of Aluminum Foil 27mm x 48mm.


  1. Cut a section of 2-Inch Clear Packing Tape at least 100mm long.


  1. Place the rectangle of Aluminum Foil on the sticky-side bottom end of the 2-Inch Packing Tape.


  1. Wrap the tape completely around the Aluminum Foil


  1. Cut/Trim the Tape edge a hair away from the Aluminum edge to prevent any aluminum exposure.


  1. Place the tape-insulated aluminum foil over the Ebyte Radio as shown to prevent High-Power transmits from causing Arduino reboots.



B.Back-side Fasteners

  1. Plug the AMP (Arduino Mega Pro) Center to the 1W-Backplane assuring correct pin alignment.


  1. Using (4) #2-1/2” Phillips-Flat Screws fasten the Backplane (back-side) to AMPCenter.


C.Display Fasteners

  1. Plug the DispKB into the (front-side) Backplane assuring correct pin alignment and casing alignment with Center.


  1. Using (4) #2-3/8 Phillips-Pan Screws fasten the Display Casing to the Top.

D.Antenna

Attach an antenna to the SMA-K connector.



3.Battery-Tray Option $3.00

3.1Materials

A.Supplies $2.06

(1) 5.5x2.1mm Barrel Plug

9mm Insert (!NO Longer!)

$0.11/ea = $0.11

(1) 9V Battery Clip

Hard Plastic Side-Exit Wires

$0.35/ea = $0.35

(2) #4 x 3/4” Screws

Barrel Plug Clamp

Phillips-Pan Sheet Metal Screw

$0.10/ea = $0.20

(1) KCD11 3A Rocker Switch

SPST 10x15mm

$0.10/ea = $0.10

(1) #4 x 3/8” Screw

Battery Cover

Phillips-Flat Sheet Metal Screw

$0.10/ea = $0.10



(Optional) Belt Clip

55(2.6”)x25(0.98”)mm Metal

0.25” hole spacing (3mm dia)

$0.80/ea = $0.80



(2) M2.5x0.45 – 5mm Flat

Belt Clamp

Phillips-Pan Machine Screw

$0.20/ea = $0.40



B.3D-Prints $0.94

File: 9V1W.3DTray.24CV.stl

Folder: .\Tode-9V-Batt\1W\3DPrints


Layer Height: 0.2mm

Infill Density: 100%

Supports: OFF


Plastic: 32-grams @ $0.02/g = $0.64

Printer-use: @ $0.0015/g = $0.048

Power: 4h 48m @ $0.01/hr = $0.047

TOTAL COST: $0.735

File: 9V1W.3DClamp.24CS.stl

Folder: \Tode-9V-Batt\1W\3DPrints


Layer Height: 0.2mm

Infill Density: 100%

Supports: OFF

Plastic: 3-grams @ $0.02/g = $0.06

Printer-use: @ $0.0015/g = $0.0045

Power: 0h 42m @ $0.01/hr = $0.007

TOTAL COST: $0.0715

File: 9V1W.3DCover.24CS.stl

Folder: \Tode-9V-Batt\1W\3DPrints

Layer Height: 0.2mm

Infill Density: 100%

Supports: OFF

Plastic: 6-grams @ $0.02/g = $0.12

Printer-use: @ $0.0015/g = $0.009

Power: 0h 48m @ $0.01/hr = $0.008

TOTAL COST: $0.137

3.1.2Assembly

Prepare 9V Battery Clip

  1. Cut Red wire 50mm long.

  2. Cut Black wire 80mm long.

  3. Cut a piece of Red wire 50mm long.

Strip, Clamp and Solder the black wire to the Barrel Plugs long lead.

Solder the Battery Clip Red wire to one of the rocker switches terminal.


Solder the piece of 50mm Red wire (3.) to the other switches terminal on one end and the Barrel plug short lead. to the other end. Putting the switch in the Red wires path as shown.

Route the Barrel Plug and Battery Clip through the switch hole and push the switch into the casing.


Put the barrel plug in the casing and route wires as shown.

Using (2) #4 - 3/4” Phillips-Flat Screws attach the Clamp to hold the Barrel Plug into place.


Clip on a battery and stuff the wires in the pocket over the switch.


Install the

Using (1) #4 – 3/8” Phillips-Flat Screw attach the Cover over the battery.

4.BIOPH Option $4.49

4.1.1Materials $3.67

A.Parts $0.93

  • IO-Access 23BF PCB

    • Design Software: Kicad

    • Folder: \Tode-IO\Tode-BIO\kicad\IO-ACCESS\SIOST

    • Manufacturer: jlcpcb.com

    • Batch Price: $46.43 per 50

    • Pricing: $0.93/ea

B.Supplies $1.14

(2) 2x40P Male Pin Header

Dupont 2.54mm-Pitch

PCB Pin-Header Array

@$0.21/ea = $0.42

(2) 1x16P Long Leg Socket

Dupont 2.54mm-pitch

PCB Analog-IO Tode-Side

@0.17/ea = $0.34

OR –

(2) 2x8P Long Leg Sockets

@0.15/ea = $0.30

(1) 2x3P Long Leg Socket

Dupont 2.54mm-pitch

PCB Digital-IO Tode-Side

@0.12/ea = $0.12

(1) 2x4P Long Leg Socket

Dupont 2.54mm-pitch

PCB Digital-IO Tode-Side

@0.14/ea = $0.14

(4) #4 x 3/8”Phillips-Flat Screw

Front-Side to Back-Side

$0.03/ea = $0.12



C.3D-Prints $0.78


BIOPH-FrontSide.stl

Folder: ./Tode-IO-Options/Side-IO Commercial Box/3DPrints/stl

Layer Height: 0.2mm

Infill Density: 100%

Supports: OFF

Plastic: 9-grams @ $0.02/g = $0.18

Printer-use: @ $0.0015/g = $0.0135

Power: 1h 43m @ $0.01/hr = $0.0175

TOTAL COST: $0.21

BIOPH-BackSide.stl

Folder: ./Tode-IO-Options/Side-IO Commercial Box/3DPrints/stl

Layer Height: 0.2mm

Infill Density: 100%

Supports: OFF

Plastic: 25-grams @ $0.02/g = $0.50

Printer-use: @ $0.0015/g = $0.0375

Power: 3h 07m @ $0.01/hr = $0.03

TOTAL COST: $0.57

4.1.2DIN-Mount Materials $0.82

A.Parts $0.66



    (2) DIN Mount Brackets

    DRG-01 for 35 x 7.5mm DIN Rail

    Pricing: $0.33/ea = $0.66

B.Supplies $0.16

(4) #4 x 5/8”Phillips-Flat Screw

Standoff-Label

$0.04/ea = $0.16




4.1.3Diagram

4.1.4Assembly


A.Sockets in Front-Side


  1. Press (2) 1x16P Long Leg Sockets into Front-Side 3DPrint.


  1. Insert (1) 2x3P and (1) 2x4P Long Leg Dupont Sockets into Front-Side 3DPrint.

    1. Sand the socket ends for a proper fit.


B.Front-Side on PCB


  1. Press Front-Side with installed Pin Sockets into the PCB holes.


  1. Plug in an Arduino Mega-Pro for correct plug alignment.


  1. Solder the Sockets to the PCB.


  1. Trim excess Pin Length

C.Pin Headers


  1. Cut (2) 2x40P Pin Headers to 32-Pin Lengths to fit the Pin Header Array.

D.Solder Pin Header Array


  1. Install the (2) 2x23-Pin Headers into the PCB.

  1. Using (3) 1x4P Sockets keep Pin Header array pins straight.


  1. Solder all pins to PCB.


E.Attach Back-Side


  1. Place Front-Side assembly on Back-side 3D Print as pictured.


  1. Fasten with (4) #4 x 3/8in Flat-Head SMS screws.

F.(OPTION) Screw on DIN Brackets


  1. Using (4) #4 x 5/8in Flat-Head SMS screws attach the DIN brackets with their pry-release tabs facing the bottom to the BIOPH Assembly.


  1. Attach to desired DIN Rail.