I’m going to see if I can connect the Nordic Eval board to the EVK eval board.

The first thing to do is to make sure that I have all the switch settings, and jlink connections recorded.

I’m not even sure if that can be done, from a power perspective.   Not sure I dare do this.  Better ask DC.
—-
ML:

I was thinking of connecting the Nordic EVK to the DW EVK1000 board.  The EVK user manual (attached) has some words of wisdom on p12, and a diagram.Inline image 1

If I connect the Nordic to USB for power, flashing and debugs, and connect one of our batteries to DW1000 J7, what will go wrong?

 DC:

Do you know what the I/O voltage is on the Nordic eval board? It can anything from 1.8V to 3.6V. I think it must be 3.3V. That would be good, because the EVK1000 is running at 3.3V. Then the I/O voltages will be compatible. If the Nordic is running at 1.8V then there would be a problem because 1.8V wouldn’t drive the EVK1000 reliably and 3.3V from the EVK1000 to the Nordic board would overdrive it. Even if they aren’t the same the Nordic seems to be quite robust since we already did things to it that should have destroyed it but didn’t. On the other hand you don’t want to take unnecessary chances. Is there a schematic of the Nordic board or other documentation? If you think the Nordic board is 3.3V then go for it.

ML:

Here some stuff I uncovered.
Inline image 1

Inline image 2

HOWEVER I Fluked Vcc to ground on the Nordic when connected to USB and it was 2.978 which is weird.

GO or NO GO mission control? 

DC:

Go, because the reason there would be any damage is if the ESD diodes become forward biased.

Since the drop across a diode is about 0.6V, as long as the voltage on the input is less than 0.6V higher than Vdd / V+ (or more than 0.6V lower than GND / V-) it will be OK.
2.9V is pretty low but maybe the errors are adding up. Or maybe the regulator is set to 3.0V instead of 3.3V. It doesn’t matter; go ahead and try it, as long as the pins are connected correctly.

ML:

OooooKaaaaay   🙂 

<later>

ML:

So I’m out of my depth again.  The EVK1000 manual p21 shows the connections for SPI.  There is no chip-select pin.
Inline image 1 

Am I supposed to know what these SS1..3 pins are?  

DC:

These are the TotalPhase Cheetah pin descriptions.
2.1.4 SPI Pins
SCLK (Pin 7):
Serial Clock – control line that is driven by the master and regulates the flow of the data bits.
MOSI (Pin 8):
Master Out Slave In – this data line supplies output data from the master which is shifted into the slave.
MISO (Pin 5):
Master In Slave Out – this data line supplies the output data from the slave to the input of the master.
SS1 (Pin 9):
Primary Slave Select – the primary control line that allows slaves to be turned on and off via hardware control. (This SS is in the same location as the SS line of the Aardvark and Beagle products.)
SS2 (Pin 1):
Second Slave Select – an additional control line that allows slaves to be turned on and off via hardware control.
SS2 (Pin 3):
Third Slave Select – an additional control line that allows slaves to be turned on and off via hardware control.

David comes up trumps as usual!!

So let’s find the SPI pins in Nordic’s  pca10001.h header file.

#define SPIM0_SCK_PIN     23u   /**< SPI clock GPIO pin number. */
#define SPIM0_MOSI_PIN    20u   /**< SPI Master Out Slave In GPIO pin number. */
#define SPIM0_MISO_PIN    22u   /**< SPI Master In Slave Out GPIO pin number. */
#define SPIM0_SS_PIN      21u   /**< SPI Slave Select GPIO pin number. */ 

Sig_Name  nRF51822_Pin  PCA10001_Pin EVB1000_Pin EVB_Sig_Name
SPIM0_SCK         23            P5.8             J6.7       EVB.SCK
SPIM0_MOSI        20            P5.5             J6.5       EVB.MISO
SPIM0_MISO        22            P5.7             J6.8       EVB.MOSI
SPIM0_SS                  21            P5.6             J6.9       EVB.SS1
GND                             P5.9             J6.10      EVB.GND
GPIO?                                            J6.4       EVB.IRQ

DC:

Do you have a schematic of the Nordic eval board? Then I can see what regulator they are using to see if it can supply the extra current. However, I”m almost certain that it can. Neither board draws a lot of average current.

ML:

I looked around for a Nordic schematic myself, and couldn’t find one.  I googled “scematic”  and “BOM” both on the web, and our shared documents.  Nada.

Maybe a AP7333-33SAG-7   It looks like an LDO 

DC:

The part number is for a 3.3V regulator so I think you’re correct. It can supply 300mA, which isn’t a lot, but probably enough. You won’t hurt anything by trying because it has current limit protection, so go ahead and hook it up.

Leave a Reply