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How Raspberry Pi could have improved

February 13th, 2013

While the designers have done a good job in the hardware design of the Raspberry Pi, there are may things they could have done better. We will capture most important of these.

1. LAN9514 in place of LAN9412
SMSC_LAN9514

R. Pi uses the SMSC LAN9512 chip, which is a USB hub with Ethernet. Basically you get an ethernet and two USBs. The two USBs are used up easily for a mouse and keyboard. So what if you need a third USB for, say, wifi ? You are out of luck. A separate USB hub is a bad solution. They could have easily improved it by using LAN9514 in place of LAN9512 which provides 4 USBs in place of 2 USBs. You could use a mouse, a keyboard and still be left with two spare ports.

2. Composite Video not needed

Who needs Composite Video ? Looking forward, HDMI is the de facto standard for display and it is great that we have a HDMI connector. Buy who needs the composite video ? This connector is not required at all. Instead, we could place a dual height USB connector. These USB Connectors could possibly point inside ( or outside) and could make a good case of Wifi without the need of a USB Hub.

3. 2x13 pin Connector could be 2 mm pitch

The GPIO pins, serial pins are stacked as two rows of 13 pins each. The pitch of these pins is 0.1" or 2.54 mm. While this is a standard separation, we could easily opt for 2 mm pitch, another standard which is at least as widely used as 0.1". This could have given us at least 12*0.54 = over 6 mm of extra space - enough for another 2 x 3 pins. So instead of the 26 pins we could have 32 Pins. So what will we use these extra pins for ? That brings us to 4th point.

4. More Serial Port and GPIO / USB

The R.
The existing R.Pi has only one Serial port, which is used for console. If you need to use a serial port, then the console needs to be disabled. The Broadcom procesor does support at least one additional serial port, but R.Pi did not bring it outside. With the extra 6 pins, we could easily bring an additional serial port. Also we could use the 4 remaining extra pins, either for USB or for more GPIO, or some other things of our choice.

5. Ethernet Link LEDs not required

They could have instead used one of these LEDs hooked up to a GPIO for learning and general purpose. There are Ethernet connectors that come with LEDs, if they were interested in Ethernet related LEDs. My experience it, ethernet LEDs are rarely used, except during design diagnosis.

6. Switching Regulators to improve current consumption

The previous 4 option, I am 100% sure, would have made R.Pi a better pi. I am not sure about this one. R. Pi has done a great job in power design by choosing low cost ON Semi linear regulators. On side effect is that the power is lost in 5V to 3.3V and then 3.3V to 2.5V conversion. By using a switching regulator, it could reduce the current consumption to well within the limit of 400 mA ( currently it is around 470 mA). But again, I am not complaining about it. The switching regulator, increases cost, requires more board space and the gain possibly offsets the losses.

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