Hi,
I'd like to know more informations about the Flex+Scicos+Erika integration. I'll develop, using Flex Full board, three controllers for an hydraulic system using the Scicos code generator. I have the following questions in my mind :

1) When I use the Scicos code generator, does it use Erika RTOS routines ?

2) I need to design three controller running in the Flex board at different sampling times. Is it possible to manage the multi-tasking in Scicos ? Which is the best way ?

3) I've seen that the Flex Full has got inside a power supply (switching) which adapts the different voltage levels. Is it possible to use those voltage levels as output ? For example if a voltage level was 5V I'll happy to use it as power input for a optocoupler.

Thank you,
Pasquale.

Hi!

Here are some answers:

1) Yes... the ERIKA Kernel is used every time you compile code generated from Scilab. Please take a look at the files

examplespic30pic30_scicos

That is the template with ID "board_flex" which is used as default by the code generator.



2) It is not yet possible to generate out-of-the-box multirate systems using the Scilab code generator, but it will be probably soon.

A way to obtain that is to generate three separated superblocks, which do not interact. Then you have to generate the code and manually assemble them.

For now the only thing supported out of the box are single rate systems.

3) Of course you can, depending of course from the kind of load you are putting on... the switching power supply has a maximum current which can be supplied! . In any case, take a look at the schematics you find on the FLEX CD-ROM. There you'll find the pinout of the connectors, which have GND and V+ pins you can use.

Regards,

Paolo

Thank you very much.
I'll follow your suggestion for the multi-tasking procedure. I've seen the schematics and I think it depends on the LM2574 which is able to guarantee 0.5A as output current. So I think the maximum current which can be supplied is 0.5A. Is it correct ?


Thank you,
Pasquale.

Hi,

you are right, the maximum current that the LM2574 can provide is 0.5. You can use the +5V as well as the +3.3V provided by the switching regulator of flex full if you are going to power low power electronic components such as digital components (digital ports, optocouplers, ecc).

If you are going to power many devices, using the internal switching regulator, please make a rough calculation of the global power consumption. I strongly recommend you not to go beyond 0.3 A (flex does not have a thermal dissipator).

If you want to power servomotors or other "power" devices I suggest to use instead the +Vout pin (using also GND_OUT) with an additional regulator (i.e. LM7805 for servo). In this case you can power many other electronic devices depending on wich power supply you are using (the limitation in this case is your power supply and the regulator that you add).

Ciao,
Francesco.

Ok,
thank you very much. I'm gonna do a rough calculation about the current I need for the 5V devices but I think I won't have more than 0.1A.

What about a load of 12V-3A ? Do you think I can use the V_OUT and GND_OUT pins ?

What about having a common ground with all the devices (5V, 3.3V and 12V) ?

I'm trying to understand how to connect the Flex and my power PCB which has different voltage devices.


Thank you,
Pasquale.

thank you very much. I'm gonna do a rough calculation about the current I need for the 5V devices but I think I won't have more than 0.1A.

... ok

What about a load of 12V-3A ? Do you think I can use the V_OUT and GND_OUT pins ?

Unfortunately the V_OUT passes through the rectifier diodes, so you can not go over 1A of continuous current over the 1N4007. If you have to power devices that have current peaks of more than 3A the V_OUT will be ok but if the load drains 3A continuously this could damage the rectifier diodes. If you use a 12V power supply and the V_OUT remember that the V_OUT will be around 10.5V so you will have to use at least a 13V power supply.

I suggest you to use one high current power supply for Flex and your electronics ( using the +V and gnd terminal of your power supply for powering separately your electronics and Flex). Then you can use optocouplers for using the digital signals of Flex. The optocouplers will allow you to use different voltages for your electronic side.

Ciao,

Francesco.