You know a piece of tech is going to be fun to take apart when it makes you go buy a new set of bits just to be able to open it
-
That chip is a Quectel LC79D: Dual-band, multi-constellation GNSS module.
It's got support for GPS (USA), Galileo (EU), GLOSNASS (Russia), BeiDou (China), IRNSS (India), and QZSS (Japan). -
Graham Sutherland / Polynomialreplied to Foone🏳️⚧️ last edited by
@foone the presence of two separate 10-pin tag connect debug headers is interesting. at least they tell you the cable part number you need (TC2050-IDC-NL). usually the 10-pin ones are for fairly big FPGAs but I'm guessing this is more likely to be an MSP430 under the hood?
-
The big chip on the main board is another Quectel chip, an EG21-G. That's an LTE module, with support for LTE/UTMS/HSPA+/GSM/GPRS/EDGE.
It has another integrated GNSS chip.
wait what? This thing has two GPS modules!? -
our other Clearly RF Chip is this Espressif ESP32-s2-mini-1.
This does Wifi (b/g/n). -
And we've got a winbond W25Q256JV. That's a 32 megabyte SPI chip.
-
Erin 💽✨replied to Graham Sutherland / Polynomial last edited by
@gsuberland @foone Hmm, I see a Quectel modem (presumably ARM), an ESP32, and one of the headers is labeled “NRF DBG” which would imply there’s a Nordic chip in there somewhere although I don’t see that
-
And on the backside we've got a ST STM32L4S5VI. That's an Arm Cortex-M4 running at 120mhz. This variant has 2 megabytes of onboard flash memory and 640 kilobytes of ram (WHICH SHOULD BE ENOUGH FOR ANYBODY)
-
The other PCB is the front panel. It's got an LCD on it (monochrome, I think?) and an antenna for NFC.
-
@gsuberland @foone Ah I see there’s an STM32 right next to the top one and a QFN which I can’t read but is plausibly an nRF51/52 next to the other.
This thing has too many MCUs.
-
The flip side has a single chip on it: An NXP PN7150L That's an NFC controller (and an ARM Cortex-M0)
-
Plugging the battery back in, it powers on, but says it's at 0% battery.
-
It then sits on this screen permanently, saying Please Wait and an error code: 0x24007.
This is probably it trying to dial home, but since I pulled the SIM card it can't do that.
-
@erincandescent @gsuberland @foone and I thought I was bad with four STM32s and an FPGA in a complex 1U rack mount gizmo with three different boards.
-
The battery is a 3235mAh 18650 with a 5 wire plug on it.
-
I think the display has a backlight, and that thing in the bottom-left looks like an ambient light sensor, but without being able to boot the thing further I can't get it to turn on the backlight.
-
This did have a sim card in it when I got it. it's still active.
-
@azonenberg @gsuberland @foone every rental scooter board seems to be like this. The sheer lack of cost optimisation insults me.
-
And it's got a set of connectors on the back. Presumably whatever scooter this plugged into had some of these, but I don't really know why it needs SO many.
Maybe variants for different types of scooters? At the very least, I think it's hooking into a can bus and power (so it can recharge the battery, since there's no other input)
-
Graham Sutherland / Polynomialreplied to Erin 💽✨ last edited by
@erincandescent @foone @azonenberg the design kinda screams rush to market
-
@erincandescent @gsuberland @foone Yeah I'm building specialty T&M gear so with a $1K+ ten layer board and a big Xilinx I really don't care about cost optimizing the micros.