Tales from the Bringup Lab

Oxide and Friends Twitter Space: December 6th, 2021

Tales from the Bringup Lab

We’ve been holding a Twitter Space weekly on Mondays at 5p for about an hour. Even though it’s not (yet?) a feature of Twitter Spaces, we have been recording them all; here is the recording for our Twitter Space for December 6th, 2021.

In addition to Bryan Cantrill and Adam Leventhal, speakers on December 6th included special guests Nathanael Huffman, Eric Aasen, as well as Rick Altherr, MattSci, Dan Cross and Steve Tuck. (Did we miss your name and/or get it wrong? Drop a PR!)

Some of the topics we hit on, in the order that we hit them:

• [@5:57](https://youtu.be/lhji-kP3Lhk?t=357) Lay of the land
• [@6:58](https://youtu.be/lhji-kP3Lhk?t=418) Power
• [@11:14](https://youtu.be/lhji-kP3Lhk?t=674) Matt: what goes in the middle of the board?
• [@14:32](https://youtu.be/lhji-kP3Lhk?t=872) iCE40 FPGA
• [@21:20](https://youtu.be/lhji-kP3Lhk?t=1280) Taking meticulous notes
• [@25:41](https://youtu.be/lhji-kP3Lhk?t=1541) Power-on sequencing
  • Using service processor flash to store FPGA bitstream
  • Solder rework
  • include_bytes
• [@32:37](https://youtu.be/lhji-kP3Lhk?t=1957) “Zombie board”
  • Flying probe video ~2mins
  • Thermal cameras
• [@46:41](https://youtu.be/lhji-kP3Lhk?t=2801) Main chip power-on
  • Level shifters, I2C
  • Googly Eye of Sauron
  • [@55:24](https://youtu.be/lhji-kP3Lhk?t=3324) SPI wiggles (Serial Peripheral Interface)
    • Precious cargo in a rented minivan
  • [@1:02:00](https://youtu.be/lhji-kP3Lhk?t=3720) Value of record keeping
  • Power management
• [@1:09:49](https://youtu.be/lhji-kP3Lhk?t=3720) “Valley of despair”, infinite reset loop
  • SP3 socket
  • Magnet wire connecting to a pin, see picture with dime for scale > Book on ENIAC quote: when things wouldn’t work, frustrated workers > referred to the machine as the MANIAC.
• [@1:24:10](https://youtu.be/lhji-kP3Lhk?t=5050) Eric’s big breakthrough > Boom! SPI wiggles
• [@1:30:59](https://youtu.be/lhji-kP3Lhk?t=5459) “The next day we had a demo!”
  • Yet another hurdle..
  • DuPont wire
• [@1:39:39](https://youtu.be/lhji-kP3Lhk?t=5979) “These are the stories that don’t get told..”

If we got something wrong or missed something, please file a PR! Our next Twitter space will likely be on Monday at 5p Pacific Time; stay tuned to our Twitter feeds for details. We’d love to have you join us, as we always love to hear from new speakers!