Introduction: ARDUINO MONITOR FOR CONCEPT2 MODEL B C D

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The program has been written by Steven Aitken.

" Steve Aitken - 2015 - with much help in testing from Al Bates - who spent many hours with audio files retesting and retesting the methods until we settled on this one. "

Original code from Steven www.github.com/stevescot/OpenRowingCode

I split the signal that produced from flywheel on 2 monitors .

On this videos i row for 2 minute reverse .The result on the screen

Few words for the programme.

Original programme from Steven doesn't work with model B and C.( model B and C has the same sensor ).

I spent Hundreds of hours testing , writing code and fixing some bugs of programme.

The big problem WAS that it didn't have any stability for strokes .I try many diferent ways with no succes .

The solution after hundred hours was so simple .Just add 100k resistance to cable that comes from flyweel to analogRead( 1 ) .

( MAGIC ....everything worked PERFECTLY )

This solution might possibly work with the original programm of Steven Aitkens but this project has been very tired for me so I quit .that's why i left inside the programme many unusefull variables , many unusefull comments because i don't have the courage to find and delete them .( i hope someone else to do that ).

I have remove some screens like watt , kcal , graphics and settings and others ( if you want them , they are included in the original programme of Steven) , but it works perfectly for : free rowing , reverse meter , reverse time , and time intervals , screen .(all with dragFactor on screen )

I observed something strange to dragFactor , that takes place in some ergometer ( model C and maybe to model D ).The test has been done on 12 ergometers model C and 2 model D.

Some ergometer gives different drag from what i am expected . .

I belιeve that is happening because this has relationship with polarity of magnets ( north -south ) but i don't have the knowledge to prove it . ( maybe "AC to DC Power Adapter IN4007 Bridge Rectifier Full-wave Rectifier " give the solution but ... I quit . someone help for this ).

www.ebay.com/itm/AC-to-DC-Power-Adapter-IN4007-Bri...

The solution for this , is that i add one screens to regulate and find the correct value of K ( K is the basicly value which gives dragFactor ) .

The K value storage to EPROM .You do this ONLY one time then you can put the damper anywhere .

How find the correct value for K .

For model C :

1. if you have PM2 , PM3 ,PM4 is very simple:

a . Find the drag ( example 140 or about in the middle of dumper ) then change monitor and put arduino monitor .

b. Go to screen "set dragFactor" and write the number of dragFactor that you have find before with the original monitor ( PM2 etc ) and push select button twice .

c. Start rowing for 20 -21 strokes with middle power.Stroke per minute must be about 26 . Then you see the screen " finished please restart " .The monitor is ready for THIS ergometer.After that put the dumper as you wish , is READY.

ATTENTION Please make TEST . You must found the drag you have wrote before (for about 10-15 strokes ) otherwise again goto screen set dragfactor .

2 . If you don't have monitor : Get out the dumper / fan (photo).The maximun dragFactor of all model C with out dumper is 235 ( EXTREMLY VERY HEAVY ).

a .With dumper out in screen " set dragFactor " write 235 and push select button twice.

b . goto previus c paragraph .

ATTENTION Please make test without dumper . You must found 235 drag ( for about 10-15 strokes ) otherwise again goto screen set dragfactor ( if it is high ex 240 set drag to 234 ) .

I know is barbaric but is very important to do that .

For model D and possible for model E ( have he same sensor) :

1. back to way 1 :

2. With dumper out , i don't have maximun number of Drag .

For model B ( the best of all) :

Model A,C,D,and E has 14 tooth gear .Model B has 2 gear one with 13 tooth and another with 15 tooth .

DragFactor as you can see on video that i upload is exacly the same , if you put chain at gear with 13 tooth or gear with 15 tooth.

Gear with 15 tooth is easiest , gear with 13 tooth is harder but they have the same dragFactor.

Explenation for 13 and 15 tooth here www.board.crossfit.com/showthread.php?t=20648

( TIP : if you want to go faster in model C,D,E with monitor PM3,PM4,PM5 ....just replace the gear ) .

Anyway model B with bumper open dragFactor is ( i upload soon ) and with dumper close is ( i upload soon ) .

( this value are taken from monitor PM2 )

If you can find monitor follow method for model C paragraph 1.

If something goes wrong I add onother one screen which delete the K ( from eprom) and start normally .

Start from the beginning .

// Another one interesting constant is" I " which gives meter that produced from flywheel . So if you change

// that variable you can do ergometer go faster or slower .I have set this value to 0,1025. " I = 0,1025 "

// another important constant is " C " I setup up " 2.9 " ( i am not sure )

// All this changes has been done because I add 100k resistance .

MANY MANY MANY thanks to Steven Aitkens .

Step 1: Let's Make It .

1 . cover usb with tape .

2 . make cable as see in the picture with 100kΩ resistance .

3. powered from 9v rechargeable battery with on-off switch or 12v simple adapter 1.5A

4 . push some pin down ( with iron soldering ) because they connect to arduino usb and create problems .

5 . connect monitor on arduino .

6 . this simpe corner made of iron is screwing on arm of ergometer the arduino with base snaps on it .

Step 2: Upload Files to Arduino

download main.h in library of arduino

download " final_9A_with_delete_drag.ino "and open .

upload to arduino and finished .

possible problems : meters runs without stroke

- Possible in jack female the 2 cable has connection between of then or somewhere has connection between cables . I have tighten it up on board as you see on picture .

- Check if usb has connections with the pins of monitor .

A very interesting file is Ergodiplay.pdf describes where Steven found information to make the programme .

Attachments