Nov 29 2009
Getting N56FU/E6000 to work in Linux
They are many reasons why I wanted to get this meter working in Linux. But whatever your reason is, this guide is for you.
Screenshot of QtDMM 0.8.13 reading of the N56FU. This screenshot was captured from an Asus EeePC 900 running Ubuntu 9.10.
1. If you are in luck, your kernel should support CP210x USB-to-UART converts. When you plug in the meter, dmesg will happily tell you that the meter has been to attached to /dev/ttyUSBx. If that’s not the case, download the driver from Silicon Labs, compile and install it.
2. You might want to install the binary for your distro. On Debian and its derivatives, it’s “apt-get install qtdmm”. If there aren’t any precompiled packages for your distribution, download QtDMM from http://www.mtoussaint.de/qtdmm.html#download. Configure, compile and install.
3. Run QtDMM and use the following configuration:
4. With the multimeter powered on and set to USB mode, click Save and hit Connect!
In some rare cases, the meter will try forever to connect but to no avail. This happened to me on my Asus EeePC 900 with Ubuntu 9.10. After trying to ‘talk to’ the multimeter via minicom, I realized that Hardware Flow Control must be switched on, well, at least for my case. To do that, type (replace ttyUSB0 with your system’s equivalent):
sudo stty -F /dev/ttyUSB0 crtscts
Of course, it would be very troublesome if I had to do this everytime I want to work with the N56FU. Since I’ve got the source of QtDMM to work with, I might as well hardcode the flow control flag in!
On line 230 of src/dmm.cpp (0.8.13), add this following line:
attr.c_cflag |= CRTSCTS;
Save, configure and compile. Things should be working now =)