Hardware » Minutnik » Minutnik eInk

h1. Eval

h2. Hardware

Display: WSH-12561; 37,32x31,8; 200x200Pixel; eval board funktioniert

Akku: 31063 (Garmin Fenix 3) 300mAh; 300 mAh; 31,6 x 24,8 x 4,3

h2. MCU

Pixel-data is 5KB ((200*200)/8); need bigger MCU; but the STM32L433CCU6 i have is too much

STM32L433CCU6: Too much

STM32L151C6U6A waers eigentlich. USB, -128KB Flash, 32KB SRAM-, EEPROM 32KB Flash, 10KB RAM, hat USB

STM32L051C8T6; no USB

STM32L053C8T6; 11,60Euro, whatt?

STM32L151C6U6A hab ich schon "hier":http://hase.seesslen.net/redmine/projects/hw-temprec/wiki/STM32#Warehouse. STM32L151CB gibts auch noch, wenn auch teure 12.15Euro.

Check the binary size. Along with USB.

* Fonts, USB, Terminal, Debug, LUT: 29616

* Fonts, USB, Terminal, RelWIthDebug, LUT: 22884

Alphabet: 22 Zeichen * 8 Bytes= 176 Bytes. Display-Content 5000 Bytes.

32KByte koennten reichen. Versions on Display optional.

4KByte EEPROM fuer Settings.

h2. Power

Lade-Chip: https://www.mouser.de/datasheet/2/268/MCP73871_Data_Sheet_DS20002090F-2932254.pdf

VCI wants 3V3. VDDIO may be less but is not specified. Reference schematics connects VDDIO directly to VCI.

Start with 3V3.

"ad_mcp73871" is getting manufactured. Lets see how it behaves on V_OUT.

V_OUT is ok. But there is no discharge protection. Additional chip needed like:

* AP9211; normal 3.0μA (Typ.), 4.5μA (Max.); Power-Down 0.1μA

"Chip":https://www.tme.eu/de/katalog/batterie-u-akku-controller-schaltungen_112884/?s_field=1000014&s_order=asc&limit=20&currency=EUR&products_with_stock=1&page=1

h2. Open points

MCU: 1.65 V to 3.6 V power supply, would need LDO. Would need this self-holding-mosfet chain. Would need seperate battery for RTC. MCU has not VBAT.

There are low IQ LDOs. "((48*1000)/1,6) / 24 / 356" = 3,511236 years.

"LDO":https://www.tme.eu/de/details/mcp1703a-3302e_db/ungeregelte-spannungsstabilisatoren-ldo/microchip-technology/

ADC can also be connected directly. Stop working at 3V. There is no "Low-Battery" signal on the ordered revision of the MCP73871.

LDO mit shutdown/enable: "AP2127":https://www.tme.eu/de/details/ap2127k-3.3trg1/ungeregelte-spannungsstabilisatoren-ldo/diodes-incorporated/

h2. Protection

* AP9211SA-AL-HAC-7 "TME":https://www.tme.eu/de/details/ap9211sa-al-hac-7/batterie-u-akku-controller-schaltungen/diodes-incorporated/

"Link":https://electronics.stackexchange.com/questions/496609/protection-ic-stopping-battery-from-charging

2x NMOS, 20V, 2A

h2. Tests

* Run with Battery < 3V; 

** -Is Shutdown of MCP73871 working- No, need additional part; AP9211SA-AL-HAC-7, AP9101CAK6-ANTRG1.

** Is Low-Battery-Detection implemented on STM32 working?

h2. Actions

* -ad_mcp73871-

* ad_mcp73871_2; Ohne das Switch-gedoens. Mit ADC Ausgang. Wiederstaende muessen ja noch nicht passen.