Hi everyone
I’m working on a small radio-related build and I think I found a handy part: the PCA9517DGKR I²C level-translator/dual-bus buffer. I'm thinking of using it to connect a 3.3 V microcontroller (for digital control) with a 5 V I²C peripheral (maybe a display or sensor), since I know mixing voltages directly can cause trouble. The PCA9517 lets me safely translate between the two I²C logic levels without damaging either side.
Plan is simple: microcontroller on the low-voltage side, I²C peripheral on the high-voltage side, and PCA9517 in between. Then I can control devices like display modules or sensor boards, maybe even interface with radio-related gear that expects 5 V I²C, using my 3.3 V MCU safely.
Before I wire things up, though, I’d like to ask you all:
If you used PCA9517 or similar I²C level-shifters in amateur radio or embedded radio builds, did you notice any quirks, like speed limitations, bus-hang when multiple devices are connected, or compatibility issues? Do you have advice on wiring / pull-ups / layout when mixing I²C buses on different voltages , any gotchas I should watch out for? For radio-related gear (with possible noise or long cables), does using level shifting I²C cause extra problems for signal integrity or EMI?
If you have experience with mixed-voltage I²C on radio or sensor projects, I’d appreciate your input.
I’m working on a small radio-related build and I think I found a handy part: the PCA9517DGKR I²C level-translator/dual-bus buffer. I'm thinking of using it to connect a 3.3 V microcontroller (for digital control) with a 5 V I²C peripheral (maybe a display or sensor), since I know mixing voltages directly can cause trouble. The PCA9517 lets me safely translate between the two I²C logic levels without damaging either side.
Plan is simple: microcontroller on the low-voltage side, I²C peripheral on the high-voltage side, and PCA9517 in between. Then I can control devices like display modules or sensor boards, maybe even interface with radio-related gear that expects 5 V I²C, using my 3.3 V MCU safely.
Before I wire things up, though, I’d like to ask you all:
If you used PCA9517 or similar I²C level-shifters in amateur radio or embedded radio builds, did you notice any quirks, like speed limitations, bus-hang when multiple devices are connected, or compatibility issues? Do you have advice on wiring / pull-ups / layout when mixing I²C buses on different voltages , any gotchas I should watch out for? For radio-related gear (with possible noise or long cables), does using level shifting I²C cause extra problems for signal integrity or EMI?
If you have experience with mixed-voltage I²C on radio or sensor projects, I’d appreciate your input.
