ELV Max! Hardware & Cube firmware
Posted: Sun Dec 18, 2011 8:46 pm
I haven't actually started using my Max! system yet, but I thought I'd take some components apart to see what's inside. I started with the cube. The cube opens easily using a flathead screwdriver to wedge the bottom out of the case (no screws, it just clicks in place). The casing is mostly empty: there is square PCB at the bottom, with a wire antenna stick out vertically, it seems the only reason the case is as high as it is is because of the antenna. There is a module with three transparent plastic tubes to get the LEDs on the PCB light up at the top of the casing. The PCB is attached to the casing using two Torx T6 screws.
The cube is powered by a Atmel at91sam7x512 ARM processor [info] [datasheet]. I suspect it is running at 18.432Mhz, since there is a crystal next to it labeled "H18.432A1".
There is a second chip, the Davicom dm9161aep [info], which is a 10/100 ethernet PHY. There is a crystel labeld "H25.000A1" next to it.
There is a third, tiny (8 pin) IC labeled "Atmel 1039 / 4508041d / 5V", for which I couldn't find any documentation (but I suspect this is a voltage regulator?).
There is a second small PCB soldered directly on to the main PCB, which probably contains all RF hardware. This second PCB also contains a wire antenna. The entire PCB is covered in a metal casing, so I don't know what is in there. On the main PCB, there is a label "TRX1"
There are quite some unconnected areas on the PCB. In particular, there is an area labeled "TRX2", with a two dozen soldering pads around it. This suggests that the PCB was designed with a second RF stack in mind (perhaps because the PCB is reused from another design?)
Here and there on the PCB there are copper pads labeled "MPx" (e.g., "MP1", "MP2", etc.). I suspect these pads are used for post-production QA and testing, but I'm not sure. It's hard to tell what they connect to and they're layed out seemingly random on the PCB. The Atmel processor also doesn't seem to have any pins labeled "MPx".
There is a port labeled "J1" (just two holes, no pins soldered on), whose function is unclear (no surface traces to follow, it's probably connected on a middle level of the PCB).
There is a port labeled "ST1" (just four holes, no pins soldered on). Following the traces from the middle two pads to the Atmel processor doesn't show where they're connected (they end up under the processor). However, assuming no pins are connected twice and no traces cross, it's likely they're connected to pins 81 and 82, which are PA0/RXD0 and PA1/TXD0 respectively. These pins are the data pins of the USART (serial port) on the processor, so that makes sense. I think the pads are connected as follows: VDD / TXD0 / RXD0 / GND (left-to-right, keeping the square pad at the left).
There is a port labeled "ST2" (just four holes, no pins soldered on). Following the traces from the middle two pads to the Atmel processor shows they're connected to pin 73 and 74, which are PA27/DRXD and PA28/DTXD respectively. These pins are some kind of debug port on the processor. I think the pads are connected as follows: VDD / DTXD / DRXD / GND (left-to-right, keeping the square pad at the left).
I have taken some pictures from both sides of the PCB, I'll try posting those later this week. Update: After over a year, I finally uploaded these pictures
The availability of a serial port is nice: If we can somehow manage to get a custom firmware onto the cube, that one can probably be used to connect a relais or opentherm module for controlling a kettle :-D
The cube is powered by a Atmel at91sam7x512 ARM processor [info] [datasheet]. I suspect it is running at 18.432Mhz, since there is a crystal next to it labeled "H18.432A1".
There is a second chip, the Davicom dm9161aep [info], which is a 10/100 ethernet PHY. There is a crystel labeld "H25.000A1" next to it.
There is a third, tiny (8 pin) IC labeled "Atmel 1039 / 4508041d / 5V", for which I couldn't find any documentation (but I suspect this is a voltage regulator?).
There is a second small PCB soldered directly on to the main PCB, which probably contains all RF hardware. This second PCB also contains a wire antenna. The entire PCB is covered in a metal casing, so I don't know what is in there. On the main PCB, there is a label "TRX1"
There are quite some unconnected areas on the PCB. In particular, there is an area labeled "TRX2", with a two dozen soldering pads around it. This suggests that the PCB was designed with a second RF stack in mind (perhaps because the PCB is reused from another design?)
Here and there on the PCB there are copper pads labeled "MPx" (e.g., "MP1", "MP2", etc.). I suspect these pads are used for post-production QA and testing, but I'm not sure. It's hard to tell what they connect to and they're layed out seemingly random on the PCB. The Atmel processor also doesn't seem to have any pins labeled "MPx".
There is a port labeled "J1" (just two holes, no pins soldered on), whose function is unclear (no surface traces to follow, it's probably connected on a middle level of the PCB).
There is a port labeled "ST1" (just four holes, no pins soldered on). Following the traces from the middle two pads to the Atmel processor doesn't show where they're connected (they end up under the processor). However, assuming no pins are connected twice and no traces cross, it's likely they're connected to pins 81 and 82, which are PA0/RXD0 and PA1/TXD0 respectively. These pins are the data pins of the USART (serial port) on the processor, so that makes sense. I think the pads are connected as follows: VDD / TXD0 / RXD0 / GND (left-to-right, keeping the square pad at the left).
There is a port labeled "ST2" (just four holes, no pins soldered on). Following the traces from the middle two pads to the Atmel processor shows they're connected to pin 73 and 74, which are PA27/DRXD and PA28/DTXD respectively. These pins are some kind of debug port on the processor. I think the pads are connected as follows: VDD / DTXD / DRXD / GND (left-to-right, keeping the square pad at the left).
I have taken some pictures from both sides of the PCB, I'll try posting those later this week. Update: After over a year, I finally uploaded these pictures
The availability of a serial port is nice: If we can somehow manage to get a custom firmware onto the cube, that one can probably be used to connect a relais or opentherm module for controlling a kettle :-D