Mini-32 using the USB bootloader

[Dany]

Hi,

The board itself works very well, and also the USB bootloader (I use the one available in the mP for PIC32 IDE) works like a charm. I use it with mikroPascal.


Nevertheless I have some remarks about the mini-32 (PIC32) board documentation and tooling:

1. It would be better in my opinion to apply a PIC32 with 128Kb of flash memory, surely when using the USB bootloader (which takes already some of that). 64Kb of flash is not enough for complex/large projects.

2. It should be made very clear in the documentation, when using the bootloader, that the configuration words of the bootloader will be used, not those set in the user program. The importance of this can not be overestimated.

3. The Mini-32 documentation should contain the configuration words actually used in the bootloader (and so also by the user program).

The configuration file is:

Code: Select all

<?xml version="1.0"?>
<MCU_DEVICE_FLAGS>
  <DEVICE>
    <DEVICE_NAME>P32MX534F064H</DEVICE_NAME>
    <VALUE>
      <COUNT>4</COUNT>
      <VALUE0>
        <VAL>$1FC02FF0:$44070000</VAL>
      </VALUE0>
      <VALUE1>
        <VAL>$1FC02FF4:$00000151</VAL>
      </VALUE1>
      <VALUE2>
        <VAL>$1FC02FF8:$00148523</VAL>
      </VALUE2>
      <VALUE3>
        <VAL>$1FC02FFC:$110FF00F</VAL>
      </VALUE3>
    </VALUE>
  </DEVICE>
</MCU_DEVICE_FLAGS>

and in "readable" statements:

Code: Select all

Config File  : Mini-32 Bootloader
MLK file used: C:\Users\Public\Documents\MikroElektronika\mikroPascal PRO for PIC32\Defs\P32MX534F064H.mlk

MCU Name     : P32MX534F064H

DEVCFG3: $1FC02FF0:$44070000
SRS Select (FSRSSEL)                                  : SRS Priority 7 (= "111")
CAN I/O Pin Select (FCANIO)                           : Enabled (= "1")
USB USID Selection (FUSBIDIO)                         : Enabled (= "1")
USB VBUS ON Selection (FVBUSONIO)                     : Disabled (= "0")

DEVCFG2: $1FC02FF4:$00000151
PLL Input Divider (FPLLIDIV)                          : 2x Divider (= "001")
PLL Multiplier (FPLLMUL)                              : 20x Multiplier (= "101")
USB PLL Input Divider (UPLLIDIV)                      : 2x Divider (= "001")
USB PLL Enable (UPLLEN)                               : Enabled (= "0")
System PLL Output Clock Divider (FPLLODIV)            : PLL Divide by 1 (= "000")

DEVCFG1: $1FC02FF8:$00148523
Oscillator Selection Bits (FNOSC)                     : Primary Osc w/PLL (XT+,HS+,EC+PLL) (= "011")
Secondary Oscillator Enable (FSOSCEN)                 : Enabled (= "1")
Internal/External Switch Over (IESO)                  : Disabled (= "0")
Primary Oscillator Configuration (POSCMOD)            : XT osc mode (= "01")
CLKO Output Signal Active on the OSCO Pin (OSCIOFNC)  : Disabled (= "1")
Peripheral Clock Divisor (FPBDIV)                     : Pb_Clk is Sys_Clk/1 (= "00")
Watchdog Timer Postscaler (WDTPS)                     : 1:1048576 (= "10100")
Watchdog Timer Enable (FWDTEN)                        : Disabled (= "0")

DEVCFG0: $1FC02FFC:$110FF00F
Background Debugger Enable (DEBUG)                    : Disabled (= "11")
JTAG Enable (RESERVED1)                               : JTAG Port Enabled (= "1")
ICE/ICD Comm Channel Select (ICESEL)                  : ICE EMUC2/EMUD2 pins shared with PGC2/PGD2 (= "1")
Program Flash Write Protect (PWP)                     : Disabled (= "11111111")
Boot Flash Write Protect bit (BWP)                    : Disabled (= "1")
Code Protect (CP)                                     : Disabled (= "1")
Sign (RESERVED2)                                      : Reserved always 0 (= "0")

4. The documentation should clearly mention that (when using the bootloader) the MCU clock runs at a speed of 80 Mhz.
Also it should mention clearly that this MCU clock frequency should be chosen in the configuration settings, next to the MCU type for every user project for the MINI-32.

5. The Mini-32 bootloader link on webpage http://www.mikroe.com/mini/pic32/ refers to an old version (v2.1). The version in the IDE is more recent (2.4).

Anyway: the mini-32 is a very fine product! Thanks mE!!

[petar.timotijevic]

Hi Dany,

Thank you for your kind words and for your good suggestions.

I will forward suggestions to my colleagues responsible for this.

Thank you for participating in the improvement of our products.


Best regards,
Peter

[Megahurts]

Hi Danny,

A double Thank You for pointing out the Boot loader configuration issue. I did not know that and it probably explains many past issues I (and probably others) have had that could not be resolved.
I have to agree that putting a smaller memory resource PIC on a product board that ships with a bootloader installed is questionable practice and thinking by the designer(s).

Keeping things at low sales price is good and all, but I personally hate it more when I discover the device chosen cannot accommodate the code I wanted to make use of the products HW potential.
Maybe the HW designers are not familiar with the concept and term "Overhead"?

It would also be very nice if the products that ship with a bootloader installed also had a equivalent MCU configuration file available for users that want to overwrite the bootloader and use their project MCU configurations so modifications can be made, but have a known safe configuration to fall back on when things don't work like intended or desired.

Thanks again for posting about this and the review making us aware of the products possible limitations for complex applications, Robert.

[petar.timotijevic]

Hi Megahurts,

Yes, this is a good suggestion.

I will forward this to our development team. Completely I agree and understand request.


Best regards,
Peter