Easy wifi display and keyboard for the HP-75c

[coitboy2000]

Hi All,

Here is a list of the parts I used, embarrassingly simple.

1. A pil-IO from http://www.jeffcalc.hp41.eu/hpil/index.html#pilio that is where the real magic happens. Also need HP-IL cables obviously.

2. An ESP8266 12F development board from https://www.altronics.com.au/p/z6381-wif...ent-board/ or similar. You could save $$ by using an existing RS232 to usb cable to flash the device but this is a simple option. Also much cheaper on ebay but this link provides a good picture & description.

3. A logic level converter board https://www.altronics.com.au/p/z6390-3.3...ter-board/ Someone may be able to advise whether this is actually needed or not ? Given the ESP board is 3.3v and the Pil-IO is 5v I decided not to risk it.

4. A power supply like https://www.altronics.com.au/p/z6355-3.3...er-supply/ You have many alternatives to choose from here. Both the Pil-IO and ESP board can accept 5V to power them.

5. Firmware to flas on the ESP8266 from https://github.com/espterm/espterm-firmware or more specifically the link https://github.com/espterm/espterm-firmware/releases It would be great if someone could learn how to compile the source in Windows or Linux so the escape sequences etc can be tweaked in the code. i.e. UP arrow on HP-71b

6. ESPFlash tool from https://www.espressif.com/sites/default/....6.7_1.zip this link has the Windows version.

7. Jumper leads and solder etc

8. Breadboard or prototyping board if desired.

I have attached an image of the flashing tool for the ESP8266 to assist. You need to press the flash button and reset button on the ESP8266 device to get it into the correct mode for flashing. Power off and restart then follow the ESPTerm instructions on GitHub. You need to use a Wi-Fi device (not your phone though in my opinion) to connect to the Access Point created by the ESP8266 and then browse to 192.168.4.1 to set it up properly.

Hope this is clear enough.

Cheers