Well begun is half done. We are going to use the following parts for building the AirTalk device. Make sure you have them around before starting this adventure!
When you have received the 3 boards, it is time to make your hands dirty! To fully understand what you are doing, here is a board-overview:
1) The TashTalk microcontroller will be placed in this socket. It handles all the aspects of LocalTalk. 2) The heart of the AirTalk; the main microcontroller with integrated Wi-FI. 3) The programmer-connector
Preparation
This manual will not include compiling the firmware for the the PIC. To avoid complicated steps pre-compiled binaries are downloadable during the walkthrough. Pre-programmed TashTalk PIC’s can be found overhere.
You will need the following:
• 1x Download and install MPLAB X IPE v5.05 (Win | Mac) (newer versions may result in issues)
There are a few jumpers on the seatboard. You need to set them accordingly.
• Set J1 to “B” • Set J2 to “2-3” • Set J3 to “2-3”
Connect the seatboard directly to the PICKIT device and seat the PIC-chip on the right location on the seat board” (see backside of the seat board). This should look like this:
Programming
Connect the PICKIT to the USB port of your computer and open the “MPLAB X IPE”. When connecting your PICKIT for the first time it may start to update your PICKIT in a few automated steps. This is normal behaviour.
Settings: Make sure you enable ‘Power Target circuit from Tool‘ (Settings -> Advanced Mode -> Power). This will set 5V to the seat board. Make sure your PIC can actually handle 5V, otherwise you may burn your IC to death. Check the datasheet of the PIC for the allowed voltage range. Without the ‘Power Target circuit from Tool’-setting programming will fail.
Go back to ‘Operate‘, and select:
• Family: All Famillies
• Device: PIC12F1840
• Tool: PICKIT3
Download the Tashtalk firmware, UNZIP it, and select the .HEX file by clicking on ‘Browse’ within the “Hex File”-section.
Click on the “Programm“-button to start programming the PIC.
You will hear a beep when the programming is finished. Now you have a freshly baken TaskTalk PIC!
Finishing
Insert the PIC into the socket on the AirTalk board. Make sure your have the polarisation the right way!
•Download the ESP-IDF installer (Universal Online 2.20 installer for Windows 10/11, use the default options)
• Solder a 6-pinheader to J1 on the AirTalk board
Compiling
Open the ESP-IDF 5.0 PowerShell Browse to a working directory, like your desktop
cd ~\Desktop
Clone the https://github.com/cheesestraws/airtalk GIT repository the following command
git clone https://github.com/cheesestraws/airtalk
cd airtalk/
Start Compiling the firmware (This may take a while)
idf.py build
Programming
Connect the TTL programmer to the AirTalk board to J1 with the supplied cable. Make sure you match VCC (pin1) to the board to VCC on the AirTalk board. When you use another TTL programmer then suggested above, make sure you connect it to J1 the right way! Start programming with the following command (replace (PORT) with the COM port the programmer is connected to, like COM6)
idf.py -p flash
The tool will wait for the ESP32 to be ready. Click on both ‘RESET‘ and ‘SETUP‘ buttons simultaneously and release on the AirTalk board. The programming will start and should finish quickly without errors.
You can now safely disconnect the plug from J1 on the AirTalk board.
The top and bottom PCBs are if you want to make a “case” for it out of two other PCBs. I found this approach gave a really nice result for very little money. Here’s how I did this.
For each AirTalk, you will need:
4 x M3x15mm nylon standoffs (female/female)
4 x M3x5mm nylon standoffs (female/female)
4 x M3x15mm (or M3x12mm) nylon screws
4 x M3x5mm nylon screws
I found that either black hex standoffs + black screws or clear standoffs + clear screws looked best.
To assemble:
Take the bottom board. For each of the four screw holes, put a 15mm screw through the hole from the bottom, then put the 5mm standoff onto the screw. Screw it right down until the standoff touches the bottom board. About 10mm of screw thread should be left sticking out the top of the standoff.
Put the mainboard onto the bottom board with the four screw threads through the four holes in the mainboard.
For each of the screw threads, tighten the 15mm standoff onto the bits of screw thread that are visible. This will fix the mainboard down.
Line the four screw holes in the top PCB up with the four 15mm standoffs. Fix the top board down with the four 5mm screws.
This will result in this order of bolts and standoffs:
If your Airtalk looks like this it is ready for use!
