/rcqr01

Turning Technologies QT "clicker" (RCQR-01) hardware exploration with Nordic nRF51822. Appears to be useful for QT2 (RCQR-02) as this appears to have similar internals.

Primary LanguageC

RCQR-01 demo software

Turning Technologies QT "clicker" (RCQR-01) hardware and software exploration (WIP). My adventures in reverse engineering an interesting platform.

hardware

  • based on nrf51822 (QFAA, 16kB ram, 256kB flash, Cortex M0)
  • low ram (non 32k model) makes it very tricky to run any BLE softdevice.

Display

  • lcd 360x160 ?, 2-bit grayscale ?
  • maybe ST7586 chipset? connected to serial bus. Use SPI to transfer data to chip.
  • hacked up uGFX framework
  • extremely wierd pixel column format (packed 3 2-bit pixels per byte)
  • no per-pixel modification, so using a 1bpp framebuffer (consumes considerable amount of ram) and just flushing periodically to display chip
    • may be able to optimize this down to a smaller row buffer, and for pixel-level or window modifications, just read and rewrite and "dirty" display lines
  • Microchip MCP1256 3.3v boost converter/regulator powers lcd stuff

eeprom

  • CAT25512 512-Kb SPI Serial CMOS EEPROM

keyboard

  • 8x8 matrix, qwerty style. Glow-in-the-dark keypad is a neat touch.
  • rows have external pullups?

pinout

nRF51822 gpio component nRF51822 gpio component
00 EEP_CK 16 EEP_SO
01 LCD_CS 17 KEY_COL3
02 LCD_RST 18 KEY_ROW1
03 LCD_DC 19 KEY_ROW2
04 LCD_MISO 20 KEY_ROW3
05 LCD_MOSI 21 KEY_ROW4
06 LCD_RW 22 KEY_ROW5
07 LCD_SCK 23 KEY_ROW6
08 KEY_ROW0 24 KEY_ROW7
09 KEY_COL0 25 KEY_COL4
10 KEY_COL1 26 KEY_COL5
11 KEY_COL2 27 MCP1256_SHDN
12 EEP_CS 28 KEY_COL6
13 LCD_BACKLIGHT 29 KEY_COL7
14 MCP1256_PGOOD 30 EEP_SI
15 MCP1256_SLEEP

programming

see picture below

inside

  • unpopulated cortex debug connector pad - only vcc, gnd, swdio, swdclk populated

battery compartment

  • test points pad pinout (from left to right - ignore the pins with the larger holes)
pad destination
1 SWDIO/nRST
2 SWDCLK
3 EEP_SO
4 EEP_SI
5 EEP_CLK
6 EEP_CS
7 P0.20 ?
8 P0.19 ?
9 GND
10 VCC 3V3

pics

pcb rear

software

  • using free, cross-platform Segger Studio (only tested on mac as of yet, linux testing to come)
  • using segger j-link for swd programming and debugging
  • setup path to the nrf51 sdk. Mine is NRF_SDK_DIR=../../nRF5_SDK_12.3.0 as project macro (set on common configuration).
    • note below about needing to make two minor patches to sdk
  • display/ui framework is uGFX

TODOs

  • (maybe)implement display row-level buffering instead of huge frambuffer to save ram and draw/refresh time.
  • improve standby/sleep modes and decrease current draw. Currently get avg <1mA when display sleeping, which is good enough for me. (The 1ms timer tick is wasteful - maybe move to 10ms?)
  • uGFX offers menuing framework, look into implementing this

references

#define SWI_IRQn SWI3_IRQn
#define SWI_IRQHandler SWI3_IRQHandler