Bug #276
Sensors are 5v logic feeding into 3.3v inputs on the controller
| Status: | Resolved | Start date: | 02/06/2017 | |
|---|---|---|---|---|
| Priority: | Normal | Due date: | ||
| Assignee: | Bryan Christian | % Done: | 0% |
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| Category: | - | |||
| Target version: | - |
Description
We have somehow managed to get away feeding the 5v logic from the Hall Effect sensors into our 3.3v logic controllers (both the v0.3 controller and the in development v0.4 controller). We need to step the 5v logic down to 3.3v logic for the final design in v0.4.
History
Updated by J. Simmons over 4 years ago
- Assignee set to Bryan Christian
Bryan has researched this issue and has a proposed solution (originally posted on Discord):
SparkFun Logic Level Converter - Bi-Directional
Sparkfun's bidirectional logic level converter for stepping up/down, connect your 5V side to high, your 3V side to low. 2.95 per unit, plus they have the circuit schematic available and it's only a very small total cost in components.
- <0.21 per unit on the MOSFET and a pair of resistors
- each stepper is 1 BSS138 MOSFET from Fairchild and two 10k resistors
PBI DEV-03 covers addressing this issue. Assigning to Bryan since he has done the research.
Updated by J. Simmons over 4 years ago
- File SparkFunLogicLevelConverter.jpg added
Bryan has ordered and received the logic level converter from SparkFun (shown below next to a CHIP Pro dev board for scale). Next up is to test out that it works with Holoseat.
Updated by Bryan Christian about 4 years ago
Was able to confirm proper voltage drop using the board. We do need to provide both 5V and 3.3V to the board, which I did not do during the test. VBUS to HV on the Sparkfun board, VCC3.3 to LV on board. Sensors go on the 5V side, 3.3V for the board side. The ground is routed through the ground pins on the matching side.
Updated by J. Simmons about 4 years ago
- Status changed from New to Resolved