[Hardware Hack]
Convert an ESP-01 serial only dongle to a programmer
- It is indeed convenient to have a controller that has WIFI capability and also be very cheap for experimentation. The ESP-01 fits the bill very well as it is just sub 100 INR. It is the ESP8266 chip with more constrained resources.
- Been using these chips for a myriad of proofs-of-concept things. The pain in using these is that they do not come with a serial port that allows them to be programmed in place. So one has to rig up a programming circuit that provides all the relevant logic levels and an external serial dongle to program them. As this chip has only 4 usable pins programming and operational setups have to be different, it is a painful to move the module from one to the other.
- There are some serial dongles that are being sold that claim to solve this problem.
- So happened to buy a couple of them to make my life easier. Turns out the dongles were just serial port dongles to connect to the chip and not programmers, even though the documentation claimed to do so for Windows. As I use Linux it did not work for me. The default dongle is as shown in the picture above.
- Using my external bread board circuit rig-up experience I knew I had to do 2 things: provide a RESET connection for the ESP-01 to be reset and have a switch that puts the ESP-01 GPIO-0 pin to be grounded for the chip to enter PROGRAM mode. The ESP8266 expects these pins to be in a certain state to be in program mode.
- The additions to the dongle are as shown in the picture above. There is a red reset switch connected to the ESP-01 to push it into reset and a black toggle switch that connects the chip's GPIO-0 pin to ground.
- The above was the output of the IDE when it tried to program the chip before the hack.
- It would fail after a time as the chip would not get into program mode.
- And after the hardware hack and toggling the GPIO-0 pin and pressing the reset to the chip, it happily goes into program mode and writes new firmware onto the chip.
- Another teeny 2 paisa worth of happiness that the hack works.
- Standard disclaimers apply. It works for me, try it at your own risk 😆
