diff --git a/SP108E-HardwareAnalysis.md b/SP108E-HardwareAnalysis.md new file mode 100644 index 00000000..d4680a83 --- /dev/null +++ b/SP108E-HardwareAnalysis.md @@ -0,0 +1,68 @@ +So far I analyzed it is equipped with these chips: + +* ESP-12F +* STM32F-030C8T (Cortex M0) +* Winbond 25Q32 (EEPROM) +* 74HC245 +* XL1509 3.3E1 (Step down regulator) +* RX/TX of STM is connected to ESP. +* 74HC245 buffers the outputs + +ESP is connected to the STM RX/TX pins. No other connections seen. +We can assume there is some firmware in the STM that does the low level connection to the LEDs. + +Question is how does the ESP communicate with the STM and what exactly does the STM at all. +But we can mod the hardware so the ESP can talk to the LEDs. + +I made some pictures with phone and microscope. + +PCB + +![sp108e-board](https://user-images.githubusercontent.com/19874899/46249775-120aba00-c42f-11e8-8d2e-4262cb47cb9f.jpg) + +Open the housing, see the red marks for the holders) + +![sp108e-openhousing](https://user-images.githubusercontent.com/19874899/46249835-0ff52b00-c430-11e8-923b-1fa1cac6d1e5.jpg) + +RX/TX connection ESP to STM + +![sp108e-rxtx-](https://user-images.githubusercontent.com/19874899/46250002-eee20980-c432-11e8-8ffe-45bd28b71893.png) + +STM32F0 + +![sp108e-stm32](https://user-images.githubusercontent.com/19874899/46249854-5fd3f200-c430-11e8-8168-6ba2791b891b.png) + +EEPROM + +![sp108e-eeprom](https://user-images.githubusercontent.com/19874899/46249886-06b88e00-c431-11e8-8515-0e86427c0bf8.png) + +Pins lead to the STM32F0 (Firmware flash? Debug?) + +![st108e-stm-32-externalconnections](https://user-images.githubusercontent.com/19874899/46249852-5b0f3e00-c430-11e8-81dd-7378074edfba.png) + +ESP-12 and its pins + +![sp108e-esp-1](https://user-images.githubusercontent.com/19874899/46249871-c78a3d00-c430-11e8-9c12-9f29d7a511fb.png) + +![sp108e-esp-2](https://user-images.githubusercontent.com/19874899/46249872-c9540080-c430-11e8-85ed-db5366b03e74.png) + +Buffer chip 74HC245 + +![p108e-hc245](https://user-images.githubusercontent.com/19874899/46250003-fa353500-c432-11e8-9035-897927aff6f2.png) + +Traces on bottom side from STM to HC245 (actually R3 and R4) + +![sp108e-traces-to-hc245](https://user-images.githubusercontent.com/19874899/46249954-1edcdd00-c432-11e8-8ad9-bcf360485a50.png) + +For the hardware mod to make it working without the STM32F0, there are several ways: +### 1. Cut traces and add wires +We need to break one of the traces on the bottom of the PCB. Then connect GPIO4 of ESP-12 with R4. +Also RX/TX connection between STM32F0 and ESP-12 need to be broken up. + +### 2. Hold STM32F0 in reset +This is the simpler method, no cuts on the PCB required, just two additional wires. +- NRST of STM32F0 to GND +- IO4 of ESP-12 to R4 + +See [**here**](SP108E-HardwareMod) for details. +