Raspberry Pi A+ USB Connector Pin Issues
We are very pleased with the new Raspberry Pi A+ from the Raspberrypi.org foundation. We are using it in our new Solar Powered Raspberry Pi Weather Station. However, there is a problem with the Raspberry Pi A+ USB Connector.
The power consumption reduction from the Raspberry Pi A makes our solar power projects more efficient. The 43% power reduction from the A to A+ is very significant.
Our problem with the Raspberry Pi A+ has to do with the USB dongle connector. It is much less robust that the B+ and older devices. The pins are easily bendable when you insert a USB Dongle such as a WiFi Dongle. We bent the pins of two different Raspberry Pi A+ boards (ruining them) before we figured out what was going on.
You need to be very careful and slowly work the USB Dongle into the connector. Then pull it out and make sure the pins are not bent and reinsert, again carefully. If you bend the pins you can short out the USB Dongle as well as destroying the Raspberry Pi A+ USB connectors. We destroyed a WiFi dongle in this manner.
The USB socket on the A+ appears to be a different socket compared to that on other Raspberry Pi boards.
Love the Raspberry Pi A+, but the USB socket is marginal at best.
Here is our latest power consumption chart for the Raspberry Pi family. These are measured values using the SunAirPlus board with the embedded INA3221 measuring the currents and voltages. Note that these include using an USB WiFi dongle for connection and we have turned the HDMI connector off (/opt/vc/bin/tvservice –off).
| Model A | Model A+ | Model B | Model B+ | Model Pi2 B | |
|---|---|---|---|---|---|
| Current (mA) | 260(200) | 195(135) | 480(420) | 290(230) | 304(240) |
| Power (W) | 1.3 | 0.975 | 2.4 | 1.45 | 1.52 |
| Source | Measured | Measured | Measured | Measured | Measured |
All of the above measurements include about 60ma for the USB WiFi Dongle! Parenthetical numbers are without the 60ma.
Hi. Have you ever noticed if the A+ board drives less current than the B+ via USB port?
I’m asking because I work developing embedded systems and recently started to use A+ board instead B+ on my project.
I noticed that using the same USB wifi dongle, the signal is significantly poor at A+ boards compared with the B+.
For example: measured with iwconfig, both boards connected at the same router at the same position, B+ has 80% of signal level and A+ has 20%. It was a bad surprise for me.
Since then, I’m searching for a reason for this.
Best regards.
Fernando,
That is very interesting. Do you have a USB plugin current meter (like: https://www.adafruit.com/products/1852) that can measure the current and voltage being supplied to the USB port? That’s the first thing I would check. If those values are the same between the A+ and B+ board, then I would say it is a software problem.
SDL
I don’t have one but I’ll arrange, may be construct one at my lab.
I’ve already tried to power the USB wifi dongle from a USB hub while de A+ is powered from another source but the hub is not so reliable and the result is the same, first I’ll try another hub and see what happens.
Indeed using the same kernel, consequently the same module, the problem persists.
Thanks for your reply and I’ll inform any result, maybe to add at the list of the A+ issues, =)
I’m also trying to grab some information at RPi forums, but appears to be a very unique situation. My next plan is to embedded a wireless transceiver at my own shield and release the USB dongles.