Created SP108E HardwareAnalysis (markdown)

SP108E-HardwareAnalysis.md

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+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.
+