September 4, 2020
Onboard is an Atmel ATSAMG55J19. This is a Cortex-M4 ARM with fpu that will run at 120 Mhz. It has 512K of flash and 176K of SRAM. It would be great if there was access to SWD pins and/or a serial port. The following article talks about what is necessary to hack one of these.
The original REV-01 dash (product JK76PL) was based on an ST STM32F205 microcontroller and was much more hackable than the REV-02. It also used a lithium cell rather than a removable alkaline cell, not that that matters terribly much these days.
Lots of these are for sale on Ebay, but nobody is promising to deliver JK76PL units.
The old Dash was based on an STM32F205RG6 from ST (an ARM Cortex-M3 running at 120 Mhz) with 1M of flash and 128k of ram, along with a Broadcom wireless chip. Anything Broadcom makes me grimmace since they are stingy and secretive with documentation -- avoid them! This unit also includes a 16 Mbit flash chip, a Micron M25P16.
The new Dash is based on an Atmel AT SAMG55J19A-MU (an ARM Cortex-M4 running at 120 Mhz -- with floating point!!). The new unit has an Atmel ATWINC1500B wireless chip. One has to applaud the departure from Broadcom, but only time will tell how easy this new combination will be to hack. In addition, the new unit has a Bluetooth chip - the Cypress CYBL10563-68FNXI. I haven't seen anything from Cypress in a long time, so this is an interesting turn of things. The new unit has a 32 Mbit flash chip (apparently a Micron N25Q032). This is 4Mbytes of flash, double what was on the previous unit, which is pretty amazing. It does have SWDIO and SWCLK, along with additional debug pins (maybe full up JTAG).
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