I couldn't reply to the existing thread so continuing in a new thread, mods may want to merge threads however
This is the existing thread:
https://www.eevblog.com/forum/projects/ten-dollar-pic-100khz-2-4ghz-frequency-counter/Just thought I'd add an update to this thread, there seems to be a slightly updated version of this available now.
I picked mine up for £8.72 on eBay, shipped from Hong Kong, only took about a week to arrive to the UK.
The device was in a typical Antistatic bag and labled as a Sanjian Studios PLJ-8LED, the PCB silkscreen has the model PLJ-8LED-R5,
I have to be fair, I wasn't expecting much for the money but it works really well!, as I'm a radio ham as well it will have many uses on my work bench.
Differences I can see so far to other versions are:
PIC Microcontroller is not on the rear, it's under the LED Segment display, not sure of the type without connecting to it Via the ISCP port or removing an LED Segment, it appears to be a QFN package.
There is a TM1639 LED Driver IC on the rear.
Voltage regulator is a ST L7805CD Linear regulator, I noticed some other versions have a switching regulator so pleased about this.
This was advertised as up to "2.4GHz" Some are advertised as up to "1.1Ghz", the prescaler is a Fujitsu MB506 which is the correct 2.4GHz part, I know some came with MB501's, however I doubt I will be using it on anything over 500MHz.
I tried it out on a few things and am very impressed for the price, there is one Gotcha though on all of these... On the signal input the red wire goes to ground rather than signal input, just pay attention to the boards silkscreen rather than the cable colour, they could have rotated the socket on the signal input to resolve this.
Here are some pictures of mine, also a picture of the firmware version, you can get this by holding the top button while applying power, but this will reset your settings too.
I managed to find a English manual online, with some additional information added, however this is for the C3 revision, but aside from PCB Layout/Component differences the operation is the same:
http://www.zl2pd.com/files/PLJ-8LED_Manual_Translation_EN.pdfThis is the exact item/seller I bought it from:
http://www.ebay.co.uk/itm/191226437566