Hermes Lite Test - in3otd/Hermes-Lite2 GitHub Wiki
Hermes-Lite 2.0 Test and Programming
This page covers initial test and programming of an assembled Hermes-Lite 2.0 with N2ADR filter board.
Visual Inspection
Look for any obvious solder shorts or bridges, misaligned components, or poorly soldered components. In particular, check for tiny balls of solder near or in between the fine pitched leads of U2, U4, U6 and U7.
Power Supply Shorts
With an Ohm meter, it is recommended to check that there are no shorts (should measure >500 Ohm) between the following points labeled in the photograph.
- +3V3 and GND
- +2V5 and GND
- +1V2 and GND
- Vbias and GND
- Vsupply and GND
- Vop and GND
- Vpa and GND
- +3V3 and +2V5
- +3V3 and +1V2
- +2V5 and +1V2
Program and Test with Raspberry Pi
Install Raspberry Pi Image
- Download and unzip the custom Raspberry Pi Image.
- Copy the Raspberry Pi Image to an SD card, size 4GB or larger. BalenaEtcher works well. See the Raspberry Pi Documentation for more details.
Setup Raspberry Pi
- Insert the SD card with the custom Raspberry Pi Image into your Raspberry Pi 3 Model B.
- Connect keyboard, mouse, monitor, power supply and ethernet cable to your Raspberry Pi. Leave the other end of the ethernet cable free. It will connect directly to the Hermes-Lite 2.0. No router or switch is necessary.
Connect Raspberry Pi to Hermes-Lite 2.0
YouTube Video of the connection process.
- Use two 5 or 6 pin jumper cables to connect the Raspberry Pi to the Hermes-Lite 2.0.
- First row:
| Raspberry Pi Header Pin | Hermes-Lite 2.0 CN1 Pin |
|---|---|
| 40 | 1 |
| 38 | 3 |
| 36 | 5 |
| 34 | 7 |
| 32 | 9 |
| 30 | NC (hangs over) |
- Second row:
| Raspberry Pi Header Pin | Hermes-Lite 2.0 CN1 Pin |
|---|---|
| 39 | 2 |
| 37 | 4 |
| 35 | 6 |
| 33 | 8 |
| 31 | 10 |
| 29 | NC (hangs over) |
- Connect Ethernet and Power to Hermes-Lite 2.0 as shown below. The Hermes-Lite 2.0 can use a barrel connector 12V power supply supplying at least 2A.
Connect Hermes-Lite 2.0 to N2ADR Filter Board
Connect the Hermes-Lite 2.0 to a N2ADR filter board using the small jumper card with 20x2 connector as seen in the picture below.
Connect the attenuator with loopback cable as seen in the picture above. The attenuator is a common 2W 50Ohm DC-6GHz 30dB inline SMA coaxial attenuator. The one I used is marked as SMA-JK6G-30dB. Two sources for acceptable attenuators are here and here. It is important to use a 30dB attenuator.
The cable is a common 10 to 20 cm SMA male to SMA male RG316 jumper pigtail.
Shown below is a close up picture of the cable and attenuator.
Program
YouTube Video of similar program and test execution.
- Make sure the Hermes-Lite is connected to the Raspberry Pi as described previuosly.
- Turn power on to the Raspberry Pi.
- Once the Raspberry Pi has booted, turn power on to the Hermes-Lite 2.0.
- Double-click on the desktop icon labeled Program.
- After 20 to 30 seconds, you should see the message below in the terminal window.
Exit code = 0... Success [RPi] closed JTAG SUCCESS: Final configure - Close the terminal window by clicking on the top-right X.
IMPORTANT: If programming does not complete within 1 minute, remove power from Hermes-Lite 2.0 unit quickly. Do not leave powered up for a long time (>5 minutes) without proper programming.
Test
- If programming has completed successfully, double-click on the desktop icon labeled Test.
- Once the GUI opens, click Connect.
- Check to see that an IP address of 192.168.xxx.xxx was assigned.
- Click Test.
- The test will take approximately 90 seconds to execute. The longest part of the test is setting the bias. During that time, you will see messages in the text window just to the right of the Connect button.
- At the end of the test, any failing tests will be reported in the GUI as well as the terminal window. The final GUI for a successful passing unit is shown below.
More detailed test output is seen in the terminal window. An example is shown below.
Once programmed, you may rerun the test step multiple times without reprogramming if you need to debug any failing tests.
When done programming and testing the Hermes-Lite 2.0, power off the Hermes-Lite and remove all connections. Connect the next Hermes-Lite to test and power it on. The Raspberry Pi can remain on the entire time.