From f8e050226086908771ffd2f31ebe2f87ed8dcad3 Mon Sep 17 00:00:00 2001 From: Tobias Girstmair Date: Sat, 3 Oct 2020 17:59:04 +0200 Subject: [PATCH 1/1] check in assembly notes --- assembly.md | 65 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) create mode 100644 assembly.md diff --git a/assembly.md b/assembly.md new file mode 100644 index 0000000..0f2199b --- /dev/null +++ b/assembly.md @@ -0,0 +1,65 @@ +# BOM + +1x ATtiny4-TS +1x 0806 100kΩ resistor +1x 0806 200Ω resistor +1x 0806 100nF capacitor +1x CR927 lithium cell +1x RCA/cinch style jack; 10mm inner diameter +1x random paper staple + + + +# Tools + +- AVR programmer (e.g. [USBasp](https://fischl.de/usbasp/)) +- ZIF SOT23-6 socket +- Soldering equipment +- Side cutters +- Kapton Tape +- Abrasive paper, ~200 grit XXX/TODO: welche körnung? + +# Software + +`avr-gcc`, `avr-size` (optional), `avrdude`, `make` + +# Assembly Instructions + +1. Insert MCU in ZIF socket and flash it using `make flash`. + Note: the MCU requires 5V VCC for flashing! + Note: to flash e.g. an ATtiny9, append `CHIP=9` to the command. +2. With the chip still in the socket and powered through the programmer, switch + the supply voltage to 3v3 and attach an oscilloscope to the DEBUG pin. +3. Measure the frequency of the DEBUG signal and adjust the `CAL_MAGIC` value + until it reads 8kHz. +4. Solder all components to the (flat) flex PCB. +5. Insulate the barrel/jacket side of the battery with a thin strip of kapton + tape. +6. Bend the staple into a U-shaped clip. + The clip shall be slid over the GND via between the MCU and C1. + a) roll over on one end + b) ca. 7mm down, bend 95° + c) ca. 2.75mm down, bend another 95° + d) flare open the ends and test/adjust fitment on PCB and battery + e) cut off extra length on other end and roll it over + f) place a kapton tape flag over the arm that sits on the component side +7. Twist together 8 strands of .1mm² enameled copper wire and cut off two ca. + 15mm pieces. Solder onto the PCB pads. +8. Cut down ground clip of the RCA jack; sand off both terminals until they are + about 1.5mm proud off the surface. +9. Solder PCB to RCA jack; insulate component side with kapton tape. +10. Push assembly text-side first deep into RCA jack housing. Test for shorts. +11. Counter-rotate the RCA jack halfs about 3 times. This makes the wires + untwist when screwing the halfs together. +12. Fully close the RCA jack. Should take about 3.5 turns. Test for shorts and + severing of the wires. -- 2.39.3