How to identify frequency of HTCC-AB01

#1

How can I find out which frequency they are made for?

HTCC01-AB01 LoRa Band Option
#2

You can distinguish by whether have these two capacitors. If there are two capacitors, it is 868 version, if not, it is 470 version.

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01.jpg928×1175 335 KB

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#3

Thank you! So my suspicion was right, my reseller sent me 2x433 and 1x868 instead of 3x868…

#4

Oh sorry, I was wrong. First, I misread you and meant that two capacitors mean I got a 433, but it’s the other way around. I also opened the working 1th module… it looks exactly the same as the other two regarding hardware:

left: working #1, right: bad #2
IMG_3007.jpg1920×409 373 KB
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#1 can communicate form the air raid shelter to the sensors gateway in our main building 200m away. With number 2 and 3, I can’t even get a connection to the gateway from the lower floor in the same building with exactly the same firmware.
So I did a test now. I used a LoRa 32 as a ping pong base station, a fixed antenna for the cubecells and 5dBm, 868MHz, SF5, BW125, CR4/5 on both sides, distance 2m. These are the results (RX RSSI on the ESP32 side/RX RSSI on the cubecell side):

CubeCell #1: -101/ -98 //WITHOUT ANTENNA
CubeCell #1:  -71/ -51
CubeCell #2: -100/ -45
CubeCell #3:  -93/-102 //WITHOUT ANTENNA
CubeCell #3:  -93/ -51

Number 2 I could not do any test without antenna, as I soldered a 86mm wire instead of the IPEX connector.
So I think antenna switching is broken on modules 2 and 3, but I can’t see anything wrong under the microscope (well, it’s not the nicest soldering, but nothing shorted or open). I drown everything in flux and hit it with hot air. I’ll report back…

#5

Nope, same problem as before. Any ideas? I measured also (with an oscilloscope) the signals at the collector and the base of Q5 as well as Pin 4 and 6 of U2. Everything looks fine… :sob:

#6

You can use cubecell No. 1 to do pingpong test with cubecell No. 2 and No. 3 respectively, and observe the experimental results.

#7

@shaffer It’s about the same picture:

CC1/CC2:  -87/ -38
CC1/CC3:  -89/ -49
CC2/CC3:  -89/ -88