Building the Basic flasher - nlimper/Mini-AP-v4 GitHub Wiki
Collect all parts
Mount the ESP32-S3
Use a fine solder wire, and a fine tip on your soldering iron. Flux can help too. Align the ESP32-S3 module with the pads, and double check if everything is still aligned after soldering one pad. Then, solder the other pads. Make sure all pins at the three sides are connected, and there are no shorts between pins. If there are shorts, flux and/or solder wick will help. The 9 bottom pads don't need to be soldered. Take extra care for the pins directly adjacent to the antenna: these ground pads need a little more heat before the solder flows.
Make a tiny solder bridge between the pins shown on the picture. This is to let the ESP32-S3 know that there is no ESP32-C6 available, so it will not show a failed state.
Flash the firmware
Now, at the back of the PCB, solder a temporary wire between the pad marked 'S3-IO0' and 'GND'. Connect the PCB with a USB-C cable to your computer. The ESP32-S3 will be in download mode. Visit http://install.openepaperlink.de/, choose 'mini AP v4', connect, and choose the right COM-port. Then, click 'install'. The procedure will take a few minutes. If your browser complains about a non-responding web page, just click 'wait'. After flashing, disconnect the temporary wire again.
Connect the AP with a USB cable to your computer again. Use one of two methods to enter WiFi credentials:
- Connect to the 'OpenEpaperLink' WiFi SSID with your phone, and visit http://192.168.1.4/setup to enter your WiFi credentials . You will have to find out the ip-address of the flasher by looking in your DHCP server, do a network scan, or connect the serial terminal and look for the ip-address in the info during startup. Visit the ip-address using your browser to go to the main interface for managing the Access Point.
- Wait until the AP flashes Red, Yellow, Red. Visit http://install.openepaperlink.de/, choose 'Mini AP v4', connect. Choose 'connect to WiFi' menu option, and select your network and enter the credentials. If that succeeds, there will be an option 'visit device' which jumps to the assigned ip address. From there, you will find the main interface for managing the flasher.
As a final step, you have to go to the config page (cogwheel icon) and click save (even if you don't change settings). The flasher icon will appear.
Your flasher is ready to use. Congratulations!
As the PCB is produced as a prototype for an access point, in theory, you could just mount a ESP32-C6 to make it an access point. The ESP32-S3 and -C6 design of the prototype didn't have any issues. The issue is at the display port, of which the pins are wired upside down. Using the PCB as a flasher (without display), there's no issue using it.