What test points are needed?

[charlespax]

There are test points on the thermocouple pads. Where else should they be? This is needed for any test fixture that is made for production.

[Tsillen]

Power points mostly, the rest can be checked by using functional tests.

[charlespax]

Here are the places I've been testing:

• USBVCC
• VBUSIN
• VBUS
• 3.3V
• GND

I think we can drop test points on just about every net.

[charlespax]

LCD test

This is probably best done after an LCD is installed in the unit. This should be done at the factory.

Battery power test

We can add test points to inject battery voltage at the battery connector. This confirms the unit can operate under battery power.

We can read the battery charging voltages from the same contacts.

USB power test

Add test points directly after the USB connector. We can test if the unit can operate under USB power. This will not test if the unit actually works when plugged into USB because the connector of joint can be bad. Maybe we should test while plugged into USB since we have to program anyway.

ADC

There are already test points for the thermocouple contacts. Inject thermocouple voltages to see if we get the expected values.

SD card

The SPI lines are already broken out to a header. Write to SD card. Read data.

ATmega32U4

Flash the bootloader and firmware. We can have a test firmware that verifies the components work. Then flash the proper firmware.

1 MM flash chip

Write to flash. Read data back.

RTC

Set the time. Read it back. Set alarm. Check if alarm triggers. The alarm triggering is critical functionality.

[Tsillen]

If the host chip was more powerfull you could build an secondary bootloader for foolproofness and testing of the board. The girl from embedded.fm mentioned that in one of their podcasts (you could mail her and ask which one it was) but it is also probably in her o'reilly published book making embedded systems. http://shop.oreilly.com/product/0636920017776.do

The test you added now looks good.

[charlespax]

@Tsillen that would be awesome! At some point we'll move to ARM and be able to do that. It certainly would be nice to have a POST. I'll add this to my notes for future products.

[samchoy88]

Currently at Rev 0.9 has following test point: -GND -3.3V -VBUS -USBVCC -VBUS_IN -VBAT

But I think we need more test point and verify following signal:

• BATT_STAT
• VBAT_SENSE
• VBAT_EN -3V3EN

[samchoy88]

Test point list in Rev 0.10:

• 3.3V
• GND
• VBAT_SENSE
• LCD_BL
• BATT_STAT
• VBUS_IN
• VBAT
• SD_CS
• FLASH_CS
• SW_PWR
• PWR_ON/OFF
• USBVCC
• VBUS

[samchoy88]

Added ISOTHERMAL GND test point (at the top of the board) to make sure ISOTHERMAL connected to normal GND.

[charlespax]

I think we can close this out. If we need other points for the test jig, we'll have to open other issues.