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Random Information Dump

Random Information Dump

Owned by Kiran Surendran (Deactivated)
Last updated: 2021-11-06 by Daniel Puratich (Unlicensed)

Replacing Safety (F0 vs F1 vs ESP32):

  • ESP32

    • Versatile,

    • Don’t need ESP32 beefiness + wifi

    • Accurate timers + spi bus are requirements for safety + 16 channels + 15 out (50Hz) + 1 input

    • WONT need wifi on safety

CV Processing (Jetson vs RPi4):

  • Firmware has handled this really well

  • Nvidia Jetson Research Page

  • Current CV Laptop Specs

    • Model: Lenovo Thinkpad T490

    • Processor: i5-8265U base 1.80 GHz boost 3.90 GHz 4 cores 8 threads

    • Memory: 8 GB (2x4) at 2400

    • Storage: SKHynix_HFS256GD9TNI-L2B0B 256 GB SSD

    • Graphics: Intel UHD Graphics 620

VectorNav Connection Notes:

  • All VN inputs from VN-300 connect to the H7 microcontroller in H7PartA.SchDoc. TX1/RX1 are optional as the breakout board is also optional. Primary communication will take place over TX2/RX2. VN-300 communication is all asynchronous.

  • RESTORE_VN details:

    • If high at reset, the device will restore to factory default state.

    • Internally held low with 10k resistor.

  • Header to send the RS-232 lines to SparkFun Transceiver Breakout - MAX3232 aka a MAX3232 breakout board for conversion into TTL. In our case the board only performs a bit flip thought it is capable of voltage scaling as well.

    • The header we use is a six pin header. This is because the MAX3232 can convert 2 Rx/Tx pairs, but we’ll only need to do one conversion maximum.

    • The pin ordering is exactly as is specified in the MAX3232 datasheet.

  • The header is optional if firmware wants to use the second set of rx/tx.

  • Rx/Tx comes in from VN is _VN, they are flipped on the H7PartA page when they are connected to the microcontroller.