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Comments by Kevin
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New product: A89301-Based Sensorless Brushless Motor Controller, 50V, 11A
- 6 October 2025Hello,
The A89301 can brake the motor, but we are not aware of anything special that it does to support regenerative braking or four-quadrant control.
Kevin
New product: A89301-Based Sensorless Brushless Motor Controller, 50V, 11A
- 22 September 2025Hello, AnotherCG.
Did you see the frequency limit for the A89301 mentioned somewhere else besides our product page? I don't remember seeing it directly mentioned in the datasheet.
The A89307 appears to use the same 11-bit representation of rated speed and speed demand as the A89301 and the same conversion factor to Hz (0.530), so we would expect it to have the same frequency limit.
Kevin
New product: VL53L5CX Time-of-Flight 8×8-Zone Distance Sensor Carrier
- 9 January 2025Hi, Herbert.
I mostly used the examples included with ST's VL53L5CX ULD API as a starting point for testing the sensor. I generally used continuous mode and the maximum frequency available (60 Hz for 4x4 zones or 15 Hz for 8x8). I don't think I did much to change the default integration time or try to calibrate the sensor.
If you continue to have trouble, you might want to post on our forum or ST's community site (they are usually pretty helpful if you have specific questions about setting up the sensor or how it works).
Kevin
New Pololu distance sensors with digital and pulse width outputs
- 2 June 2021Hello, Matt.
For objects to be detected by any of these sensors, the minimum distance is less than 5 mm; for an accurate measurement from the pulse width versions, the minimum distance is about 1 cm. We do not have the accuracy precisely characterized, but the graph of measured vs. actual distances on the pulse width version's product page should give some idea of typical accuracy (this includes timing uncertainty specific to the pulse width output).
Kevin
New Pololu distance sensors with digital and pulse width outputs
- 10 February 2021Hi, Mark and Ron.
Like most sensors that use infrared light, the Pololu Digital Distance sensors are affected by daylight (and any other background infrared light) since it basically reduces their signal-to-noise ratio. They will generally still work, but you might see a significant reduction in effective range depending on the intensity and direction of the sunlight.
Multiple sensors shining at each other (e.g. on two different robots) can interfere with each other, but we haven't observed any significant interference between two side-by-side sensors pointing in the same direction, so having multiple sensors on the edge of a robot like you described should work fine.
Kevin
Now available: VL53L1X library for Arduino
- 8 February 2021Hello, Kent.
Our VL53L1X Arduino library does not support changing the ROI and calibrating the sensor at this time, so if you need that functionality, you should probably use one of the official ST APIs like you mentioned (either the full or ultra lite API). We do have an implementation of the full VL53L1X API for Arduino, although we do not have a port of the ultra lite API. From a quick web search, I found that someone else made this Arduino port of the VL53L1X ULD, so that might be useful to you, although we have not tried it.
Kevin
New product: USB 2.0 Type-C Connector Breakout Board
- 18 May 2020Hi, Paul.
It looks like you also posted your question on our forum; I have replied to it there.
Kevin
New product: USB 2.0 Type-C Connector Breakout Board
- 14 May 2020Hi, Steven.
I'm not sure what you're asking; USB does not allow devices to be daisy-chained, so you typically need a hub to connect multiple devices to a host. If you have additional questions or would like to discuss this further, please post on our forum, which is more suited for technical discussions.
Kevin
New product: VL6180X Time-of-Flight Distance Sensor Carrier
- 5 May 2020Hi, jovial_cynic.
If the sensor used only the amount of reflected light to estimate distance, it would be significantly affected by the reflectance of the target (a target that is more reflective would reflect more light, and the sensor might interpret that as the target being closer). By using a time-of-flight measurement instead, the VL6180X should be able to measure the distance more accurately because time of flight should be independent of the reflectance of the target. The graph in the post above (from page 12 of the datasheet) shows that the performance should not vary much with targets ranging from 3% to 88% reflective.
In practice, how much light the target reflects does make some difference, and I think it mainly comes down to signal-to-noise ratio: a large bright target gives a stronger signal than a small dark one, which gives the sensor better data to estimate the distance with. If you look closely at the graph, you can see that the 3%, 5%, and 17% lines are all generally "spikier" than the 88% line; the readings are noisier and less accurate with less reflective targets.
If you're having trouble getting good results, you might be pushing the limits of the VL6180X's capabilities, so you might consider trying the VL53L0X and/or VL53L1X, which are similar sensors optimized for longer ranges (so I also expect them to do better on challenging targets at shorter ranges). Or if you want to try to improve your current system using the VL6180X, you could post on our forum with details of your setup and your code.
Kevin
Kevin's mini-sumo robot: Roku
- 4 December 2019George,
The comments here are not a great place to post code or help you troubleshoot your system, so please post on our forum and I or another member of our tech support staff can try to help you (including making my code available there). So that we can look for any issues in your setup, it would be useful for you to provide more information, including pictures of your connections, the code that you are trying to use, and a description of the behavior you are seeing compared to the behavior you expect.
Kevin