The Yocto-PWM-Rx is a 2 channel PWM input. Each channel can report frequency, duty cycle, and pulse length. It works from 0.05Hz to 250Khz and accepts any -30..+30V signal as long as it crosses the 0.7V threshold.

Each channel also features a pulse counter linked to a time counter. This allows it to integrate over time the output of sensors such as flow-meters. The pulse counter works from 0 to 250kHz.

The two PWM inputs are galvanically isolated from the USB bus. This allows you to connect the Yocto-PWM-Rx to main-powered equipment without risking to fry your computer.

This device can be connected directly to an Ethernet network using a YoctoHub-Ethernet, to a WiFi network using a YoctoHub-Wireless-n and to a GSM network using a YoctoHub-GSM.

Yocto-PWM-Rx Yocto-PWM-Rx Yocto-PWM-Rx

USB cables and enclosures to be ordered separately.

CHF 60.00

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Hardware release:Rev. B
Product ID:YPWMRX01
Product name:Yocto-PWM-Rx
USB connector:micro-B
Frequency:0.05 ... 250'000Hz
Refresh rate:50Hz
Input impedance:110KΩ
Max working voltage:-30 ... +30V
Threshold voltage:0.7V
Protection class, according to IEC 61140:class III
USB isolation, dielectric strength:1kV
Normal operating temperature:5...40░C
Extended operating temperature2:-30...85░C
Supported Operating Systems:Windows (PC + IoT), Linux (Intel + ARM), macOS, Android
Drivers:Driverless, no driver needed
API / SDK / Libraries:C++ Obj-C C# VB.NET UWP Delphi Python Java Android LabVIEW
API / SDK / Libraries (TCP only):Javascript Node.js PHP
RoHS compliance:RoHS III (2011/65/UE+2015/863)
Suggested enclosure:YoctoBox-Long-Thick-Black
Harmonized tariff code:9032.9000
Made in:Switzerland

1 These specifications are for the current hardware revision. Specifications for earlier revisions may differ.
2 The extended temperature range is defined based on components specifications and has been tested during a limited duration (1h). When using the device in harsh environments for a long period of time, we strongly advise to run extensive tests before going to production.

Accessories and related products

YoctoBox-Long-Thick-Black, Enclosure for Yoctopuce device (long, thick, black)Fix-2.5mm, screws and spacersUSB-A-MicroB-50, USB 2.0 type A to Micro-B data cable, 50 cmYoctoHub-Ethernet, Ethernet-enabled hub for Yoctopuce modules

Related articles and application examples


User manual (HTML)
User manual (PDF)
Product brief
3D file (STEP)
RoHS certificate
Most recent firmware52757 (01/11/2023)
Programming libraries61813 (07/05/2024)
Command line API61813 (07/05/2024)
VirtualHub application61813 (07/05/2024)

Add a comment 8 comments

1 - cjw Sunday,march 12,2017 9H39

I'd like to change the frequency Hz value to CPS (Counts per Second). I'd also like change the reported edge count to a singular event per pulse (1/2 value). How do I do this ?

Is there a way of simple doing this without digging to far into the APIs?

2 - martinm (Yocto-Team)Monday,march 13,2017 6H42

@cjw: The unit is hard-coded into the device and cannot be modified. The events count is done in hardware, and this hardware cannot tell the difference between up and down transitions, that's why the device reports edges count, not pulses count.

3 - cjw Monday,october 09,2017 19H35

I previewed the new firmware that you released last week Oct.4/5 and it works well overall.
Excellent functionality when measuring above ambient background. My radium check source that was measured with a Ludlum 2221 scaler/ratemeter with a LND7317 shows 12,600 - 14,000CPM. averaging this out over a 10 minute time window I get the same ~12,940CPM - 13,000CPM that the Ludlum scaler shows. LND7313 CPM- uSv/hr is 3450:10.

The only thing that I see that could be fixed is that the firmware now ignores low counts and generally starts counting around 0.5 - 1CPS...not the 0.05CPS (3CPM) which was what the Hz measurement setting was able to see.. I am guessing that there must be a sampling rate adjustment that I need to play with. I should be able to adjust the sampling time to 1000ms for each sample on CPS.. CPM also shows the same blindness to lower counts.

4 - cjw Saturday,november 11,2017 7H18

Just got the micro connectors to add an extra connection to the board and was adjusting the API in the window while on a PC. I changed the setting to display the pulse length and the PMW-Rx disconnected and refused to reconnect. It will not show up anymore as a device in the newest edition of Virtual-Hub. What I do I get is the Virtual hub settings API. I tried searching for the device in the search bar underneath in the Virtual hub and a message stating that it is in a reflash state, I attempted reflashing the board but I get an error doing so and a message stating that the reflash failed.

I was just about to integrate this into my Bicron surveyor MS.
So much for that idea.

Confused as to why the newest Virtual-hub release would seemingly brick the board like this.

5 - martinm (Yocto-Team)Wednesday,december 20,2017 7H21

Just plug the device while keeping the button pressed, and you should be able to flash it again.

6 - cjw Tuesday,january 30,2018 8H27

I have just installed the PMW-Rx RevB into my bicron surveyor MS.
I have currently reflashed the board with older firmware due to the higher accuracy of the CPM measurements.
In doing so I lose out on the ability to see low CPS, and CPM.

The newer firmware has the ability to see lower frequency, but if we were able to bring this ability to the CPS measurement and then remove the rounding (averaging) on the CPM, I think the project would be complete.

I'll test out any firmware you can do and then fire off a video showcasing the finished project!

Just about there! :)

7 - mvuilleu (Yocto-Team)Tuesday,january 30,2018 14H43

@cjw Indeed, the CPS/CPM measure returns the effective number of counts measured, and not an interpolation based on the latest observation. If the goal is simply to use the same Hz value but display a different unit, I though you could do that in software and did not need a change in the firmware...

8 - cjw Saturday,february 10,2018 8H19

The newest firmware release (custom) now solves the problems of rounding and low cps/cpm cutoff.

Everything is working how it should!

Thank you Marc and others for the help!!

Yoctopuce, get your stuff connected.