Signal Generator, MiOYOOW 1Hz-150KHz 1-Channel Adjustable PWM Pulse Frequency Generator Module DC 3.3V-30V 5-30mA LCD Display Module

I bought this panel-mount PWM generator as I needed a quick and easy way to generate square waves for a project I was working on. Originally, I was going to build one, but when I saw I could buy one for far less time and effort than building my own, I bought this one. It arrived on time and packed in a small zip-lock bag. A day after it arrived, the seller sent me a link to download the manual – that was a very nice touch and much appreciated. However, I will say that because the generator is so easy to use, you really don’t need the manual. I powered the unit on and hooked the output to my frequency counter to check for frequency accuracy. It was very close to being spot-on. For instance, when set to its maximum frequency of 150 kHz, my counter read 150.323 kHz. That’s less than 0.2% error. Next, I hooked it up to my oscilloscope to look at the output waveform. It looked really nice – I included a picture from my old but reliable Tek 465 scope. Even though I didn’t need the manual, I decided to read it. On the last page it mentions “UART Communication and Parameter Setting.” Not seeing an obvious way to connect to the unit via serial, I carefully removed the back of the unit with a spudger. On the circuit board is a space for a three pin header marked with GND, TX, and RX. I carefully removed the Printed Circuit Board from the unit, installed a header, and connected up a USB to Serial converter. I don’t recommend doing this unless you have a lot of experience taking electronics apart, as it is a little bit tricky. I used four thin metal spudgers wedged between the board edges and the housing, and it pulled out with some resistance. Using the Serial Monitor window provided by the Arduino Development Environment, I could talk to the unit, but it kept telling me FAIL. To make the serial interface work properly, you have to set Serial Monitor to not just 9600, 8, 1, but you also have to change it’s setting at the bottom to “No line ending.” Once that is done, everything works properly. If you type “read” into the line at the top and click send, it will return the currently set frequency and duty. In the pictures, I’ve got a capture showing it replying with a Frequency of 100 Hz (F100), and a Duty Cycle of 040 (D040). To set the frequency, you type “F101” and click send. If all is well, it will reply with “DOWN.” If not okay, it will say “FAIL.” To set 1.05 kHz, you’d send “F1.05” and click send. 10.5 kHz would be “F10.5”, and 105 kHz would be “F1.0.5.” I attached a photo showing this including some limits. Bottom line, this is a neat little PWM generator that is a great value…and it’s hackable to add serial communication, so you could have it mounted in a panel and both manually control it with pushbuttons as well as having serial control.

Few often realize this, but I would call myself a beginner at electronics. That being said, this is an excellent signal generator! I know it's only one waveshape, but it just WORKS. The 1hz pulse was like clockwork! The video you will see is just me noodling around with voltage, frequency, and duty cycle settings at random. I wanted to see if this thing would output a signal at all, and guess what? It does! I am using my OWON vds1022i for the measurements. I will say that my scope measured the frequency to be a bit low (maybe 29.7 Hz for a setting of 30Hz), but it really is very acceptably accurate at this level. The only thing I found odd about this unit was that, having used a WHDTS ammeter you may have heard of, it was disorienting to have the output connection at the far LEFT of the unit. WHY? Apart from that, I can heartily recommend this as an affordable beginner's signal generator that you do not have to assemble!

I really like this signal generator. It’s small and compact and will easily fit into a panel mount. The unit is affordable and contains many useful features. The generator is accurate and meets it’s specification. It’s also surprisingly easy to use with just two buttons. I haven’t had any trouble adjusting any of the parameters. I am glad I bought this unit as it will fit nicely into my DIY test equipment panel.

This product does only one thing but it does it well. The controls are easy to use and they work well. I found it had no documentation other than the 4 connection pins on the bottom. From the pictures you can see I added the documentation I felt was relevant. I do not use it every day so this helps no blowing things up and remembering the freq limits etc. The major thing for me was to remember at a glance that the output square wave voltage is the same as the input power supply. You would not want to power it with 24 volts and send the 24V signal to an Arduino for example. It has a clean signal and the PWM is very handy.

Used this in conjunction with an SSR to control a heating element. It works very well. After roughly 60 hours of use, no problems whatsoever. Build quality is fair to good. Response time on the buttons is very good. I don't have anything negative to say. For the price, it is a good deal. If you're looking for a high end frequency/duty cycle pulse generator, this is not what you want. If you need something basic that may or may not output what it says, but repeats what it does do, then this is a good choice.

Neither of the two I got worked. Are for work, have a test bench at home, took much time in testing because others in the team have already used them. Now have two useless signal generators that can not return.

I ordered this generator for my DIY projects. It was delivered promptly in a good packaging. I tested and recorded small 1 minute video. Connected to my 12v power supply and to my oscillograph. It was very simple to adjust from 0 Hz to 150 Khz as described in the listing. Also what is good about this compact generator is, you can adjust duty cycle. That is very good function of this signal generator. Over all it is good device for it's price. Recommend to any one who make small projects.

Easy to hook up and use. Worth the small cost. Handy to connect when needed