Just so I understand where you are coming from, what's the motivation for removing the microphone? We already have a couple of extra ADC inputs on the hacker port if someone needed to add another analog input. The microphone is so sensitive that it works great from across the room. I'm probably missing something.
Thanks for sending the data Michael. It is clear that the Scribbler's IR sensors are blind to the black banner material. I suspect that you could swap out the LED with a visible one as you had suggested and also use a visible light sensitive photo diode. The circuit would work with a small amount of tuning. You would probably just need to adjust the series LED resistor. Have you tried coloring the black banner lines with a black ink marker to give it more contrast?
I make translation of hints and help system for S2, including the help information on language Spin, on Russian. Whether this information interests you?
I make translation of hints and help system for S2, including the help information on language Spin, on Russian. Whether this information interests you?
Mikhail, of course this is interesting to us. Please send over whatever you've got or drop box it to me kgracey@parallax.com and we will make this available to others on the S2 page.
Heck, I might have to make a trip over to Russia pretty soon to thank you. Seems lately we've picked up a bunch of new friends there.
I know there are few Hobby RC guys on the forum so I thought I would ask if anyone has a connector suggestion for the S3's battery pack? We have settled on a LiPo Prismatic style soft pack. I would like to pick a connector which is common in the RC world so users can easily swap in a different pack if they desire although one would be included with the robot of course. It will be a 1S / 3.7V cell. The absolute max discharge current would be 5 Amps but 1-2 Amps will be typical, charge current could be up to 2.5 Amps with the right USB adapter.
Single cell LiPo packs are relatively rare in the RC world. They're generally reserved for small electric aircraft and often have proprietary connectors which wouldn't be suitable for the S3 (too small).
I don't have a suggestion on what you should use and I use a lot of LiPo packs.
I personally use Dean's style connectors on my battery packs but I wouldn't recommend them for this application. Dean's connectors used to be very common but they're no longer included with any new battery packs I see.
To my knowledge just the Spinneret has this It is SO useful. Enable reset thru serial/usb/xbee or DON'T. I would like to have that on all boards. In general.
USB enumeration on Host resets connected prop. Restart from Host resets connected prop. Connecting or disconnecting PropPlug or USB resets connected prop. Who needs this?
Having at least a jumper there enables me and other to either pull or plug the jumper, or even mount a toggle switch with some short wire. Programming/Reset on or off.
This is also the solution for that ongoing problem with sending serial data to PropPlug or USB without host connected, thereby powering up USB and resetting the prop.
It is also simple and not very expensive I guess. Two pins and a jumper.
"The great thing about standards is that there are so many to choose from."
I'm glad that I asked for opinions, I had thought the Deans style was more common.
The XT60 looks pretty interesting but it may be too large as mentioned.
I think the spark fun small JST style as well as the BEC/ larger JST style are too small for our application. The BEC might just barely be ok but we'd see some voltage drop if we put 3-4 amps through a 22 awg wire and we don't have much margin with a 3.6V cell.
I had hoped to find something which I could PCB mount on the back PCB to keep the manufacturing cost low but that's not a requirement. We could do a flying leads in line connector instead.
Here is a whacky idea, how about just a pluggable screw terminal?
Here is a whacky idea, how about just a pluggable screw terminal?
I personally love those pluggable screw terminals. I often switch out normal screw terminals for the pluggable type.
Aren't they a bit large? I would have thought they would be too bulky for the Scribbler. Though now that I think about it, I have seen small ones on devices. I just haven't seen the small one for sale outside of a device.
What about using the batteries and battery charging circuit that Parallax already sells?
I'm pretty sure one criteria is to use the USB connection for charging. I doubt Parallax's charger would work well with a USB power source. USB charging has lots of complications. I think to properly take advantage of USB power, there needs to be some communication between the device being charged and the PC.
I think to properly take advantage of USB power, there needs to be some communication between the device being charged and the PC.
I only have anecdotal evidence, but my old clamshell cell phone only uses the power lines on USB (no communication) and I haven't had a problem charging it.
In any case, there's communication via the FTDI chip. I'm not sure how to get it to ask for more power (as per spec?), but again my anecdotal evidence seems to indicate that this is not an issue for the <500mA case. I've used the MAX8819A charger in conjunction with an FTDI and I haven't had a bug report about it not charging.
But I see your point: that board doesn't have USB. Which is unfortunate...
It's very easy to pull up to 500 mA from a port although it technically violates the USB spec to do so until the host takes you out of suspend but lots of products do it anyway. What's a lot more difficult is to charge at higher currents. There are are a couple of different ways to do this including the Apple way and also USB Battery Charging which is a more standardized method. Due to the large capacity of the S3's battery, it would have taken over 7 hours to charge it at only 500 mA so I have opted to support the faster charging methods assuming the user has a wall adapter or computer capable for supplying the additional current. -Ben
I only have anecdotal evidence, but my old clamshell cell phone only uses the power lines on USB (no communication) and I haven't had a problem charging it.
In any case, there's communication via the FTDI chip. I'm not sure how to get it to ask for more power (as per spec?), but again my anecdotal evidence seems to indicate that this is not an issue for the <500mA case. I've used the MAX8819A charger in conjunction with an FTDI and I haven't had a bug report about it not charging.
But I see your point: that board doesn't have USB. Which is unfortunate...
I have always assumed that the Propeller needed to be reset prior to programming. Pardon my ignorance but is that a valid or invalid assumption? A reset jumper would have to be inside of the S3 and only be accessible after removing the screws and taking the product apart. If my assumption is true, then removing the jumper would create a non-programable robot requiring the user to take it back apart. This seems like a potentially bad user experience but maybe I'm missing something.
To my knowledge just the Spinneret has this It is SO useful. Enable reset thru serial/usb/xbee or DON'T. I would like to have that on all boards. In general.
USB enumeration on Host resets connected prop. Restart from Host resets connected prop. Connecting or disconnecting PropPlug or USB resets connected prop. Who needs this?
Having at least a jumper there enables me and other to either pull or plug the jumper, or even mount a toggle switch with some short wire. Programming/Reset on or off.
This is also the solution for that ongoing problem with sending serial data to PropPlug or USB without host connected, thereby powering up USB and resetting the prop.
It is also simple and not very expensive I guess. Two pins and a jumper.
The problem is someone might wire it backwards which would blow the charge control chip. A reverse biased diode could protect the charge chip input by tripping the battery internal PCM but that would add another ~50-100 uA of leakage current always draining the battery. Also if a user wired up a pack without a PCM by mistake, they would probably wind with a flaming Scribbler.
That leaves with either the XT60 on flying leads or something non-standard like a barrel jack or a rectangular connector like the old Tamiya NiMh packs used. If 1S cells aren't common in the RC world anyway, maybe it doesn't really matter.
I personally love those pluggable screw terminals. I often switch out normal screw terminals for the pluggable type.
Aren't they a bit large? I would have thought they would be too bulky for the Scribbler. Though now that I think about it, I have seen small ones on devices. I just haven't seen the small one for sale outside of a device.
I've only used the 5mm pitched connectors like the ones you found but I have a DVR with a 3.5mm pitch connector. This kind of seems like a more appropriate size for the S3 (at least in my mind).
Here's the mating connector in the DVR.
With the connector plugged in.
There's some writing on the side of the connector. I'll get a better look at it and add it here later.
I'm going to want to track down a source of these connectors for my own use.
I saw a reverse polarity protection circuit which used a relay. It didn't cause any voltage or current loss if the power supply was properly connected. A reverse polarity condition resulted in the relay being tripped and an error LED lit.
I think the down side to the circuit was the component cost and I also think it took up a bit of board space. I liked the design since it didn't interfere with normal use.
I'm not sure if the relay would operate fast enough to prevent damage though. I'll see if I can find the webpage again.
Duane, TE Connectivity, Molex, Phoenix Connector, and FCI make pluggable terminal blocks in 3.5mm pitch. At work, we use tons everyday in several pitches. I agree with you in needing some for my own projects and somewhere I have a huge box of 0.2" pitch pluggables in various pin counts.
I wanted to send a little update on the S3 design progress. Im happy to say that I have released the Front and Back boards for prototype production last week. I have attached the Rev A PCB schematics.
My CAD package added a 3D rendering tool in the last release, I cant decide if its actually a useful feature or not. The parts are rendered as solid rectangles unless you model them for real in a 3D tool and link them. This is adequate for most items I guess but the switches on the back board for example wind up being a lot bigger than then they are in reality.
I should have the raw PCBs back in a few days so Ill be building and debugging them up over the next few weeks along with wrapping up the mechanical changes. I have the 3D modeling complete on the front half of the robot including adding the cutout for the hacker port and the XBee module but I need to roll my UI changes and finish the battery compartment changes for the LiPo pack.
On the battery connector, I decided to just put a pair of pads for soldering wires for an inline battery connector. Let me know if you have any feedback.
On the battery connector, I decided to just put a pair of pads for soldering wires for an inline battery connector. Let me know if you have any feedback.
I don't have a very strong opinion about this but I think having a mating connector for the battery shown in post #161 makes the most sense of the options mentioned. I'm pretty sure there are multiple options for on board mating connectors. I believe the connector can handle 5A. The battery shown in post #161 is made to deliver up to 16A at 8V.
The connector shown in Post 161 is known as a BEC type I believe. The issue is that these type connectors will only take a 22 AWG wire which is going to have quite a bit of voltage drop even with the short wires at 4 Amps. With the single 3.6V cell, we don't have much voltage margin to play with. The RC cars use multiple series cells to get around this problem which would have been great for our application but would have complicated charging from the lower USB voltage. The XT60 is overkill but I think will fit if I tuck it up in side of the body to the side of the Back PCB.
Maybe I'll order some BEC connectors and measure how much drop I get at 4 Amps. I certainly prefer the size of it.
I don't have a very strong opinion about this but I think having a mating connector for the battery shown in post #161 makes the most sense of the options mentioned. I'm pretty sure there are multiple options for on board mating connectors. I believe the connector can handle 5A. The battery shown in post #161 is made to deliver up to 16A at 8V.
The connector shown in Post 161 is known as a BEC type I believe.
I find the world of connectors very confusing but I thought "BEC" was usually the abbreviation for Battery Elimination Circuit. Many electronic speed controllers will include a BEC so the receiver can be powered with the same battery used to power the motor. I'm sure many BECs used that type of connector but I'd be surprised (though not very) if the connector itself is called a BEC connector.
Comments
Just so I understand where you are coming from, what's the motivation for removing the microphone? We already have a couple of extra ADC inputs on the hacker port if someone needed to add another analog input. The microphone is so sensitive that it works great from across the room. I'm probably missing something.
Thanks,
Ben
Thanks for sending the data Michael. It is clear that the Scribbler's IR sensors are blind to the black banner material. I suspect that you could swap out the LED with a visible one as you had suggested and also use a visible light sensitive photo diode. The circuit would work with a small amount of tuning. You would probably just need to adjust the series LED resistor. Have you tried coloring the black banner lines with a black ink marker to give it more contrast?
-Ben
I make translation of hints and help system for S2, including the help information on language Spin, on Russian. Whether this information interests you?
Mikhail, of course this is interesting to us. Please send over whatever you've got or drop box it to me kgracey@parallax.com and we will make this available to others on the S2 page.
Heck, I might have to make a trip over to Russia pretty soon to thank you. Seems lately we've picked up a bunch of new friends there.
Ken Gracey
Access to the reset button would be through the shell.
Ken Gracey
XBee WiFi..a most excellent addition! Good job Parallax!
Does anything jump out as an obvious choice?
Thanks,
Ben
These XT60 connectors seem be pretty common but I think they're likely too large for your purposes.
The smaller batteries often have a connector like these.
Here's the product page for the above battery.
http://www.hobbyking.com/hobbyking/store/__9276__Turnigy_800mAh_2S_20C_Lipo_Pack.html
Single cell LiPo packs are relatively rare in the RC world. They're generally reserved for small electric aircraft and often have proprietary connectors which wouldn't be suitable for the S3 (too small).
I don't have a suggestion on what you should use and I use a lot of LiPo packs.
I personally use Dean's style connectors on my battery packs but I wouldn't recommend them for this application. Dean's connectors used to be very common but they're no longer included with any new battery packs I see.
The type of connector in the above image (breadboard friendly) would be my choice.
https://www.sparkfun.com/products/341
http://www.adafruit.com/products/258
To my knowledge just the Spinneret has this It is SO useful. Enable reset thru serial/usb/xbee or DON'T. I would like to have that on all boards. In general.
USB enumeration on Host resets connected prop. Restart from Host resets connected prop. Connecting or disconnecting PropPlug or USB resets connected prop. Who needs this?
Having at least a jumper there enables me and other to either pull or plug the jumper, or even mount a toggle switch with some short wire. Programming/Reset on or off.
This is also the solution for that ongoing problem with sending serial data to PropPlug or USB without host connected, thereby powering up USB and resetting the prop.
It is also simple and not very expensive I guess. Two pins and a jumper.
Enjoy!
Mike
I'm glad that I asked for opinions, I had thought the Deans style was more common.
The XT60 looks pretty interesting but it may be too large as mentioned.
I think the spark fun small JST style as well as the BEC/ larger JST style are too small for our application. The BEC might just barely be ok but we'd see some voltage drop if we put 3-4 amps through a 22 awg wire and we don't have much margin with a 3.6V cell.
I had hoped to find something which I could PCB mount on the back PCB to keep the manufacturing cost low but that's not a requirement. We could do a flying leads in line connector instead.
Here is a whacky idea, how about just a pluggable screw terminal?
Thanks for the feedback!
-Ben
I personally love those pluggable screw terminals. I often switch out normal screw terminals for the pluggable type.
Aren't they a bit large? I would have thought they would be too bulky for the Scribbler. Though now that I think about it, I have seen small ones on devices. I just haven't seen the small one for sale outside of a device.
I'm pretty sure one criteria is to use the USB connection for charging. I doubt Parallax's charger would work well with a USB power source. USB charging has lots of complications. I think to properly take advantage of USB power, there needs to be some communication between the device being charged and the PC.
I only have anecdotal evidence, but my old clamshell cell phone only uses the power lines on USB (no communication) and I haven't had a problem charging it.
In any case, there's communication via the FTDI chip. I'm not sure how to get it to ask for more power (as per spec?), but again my anecdotal evidence seems to indicate that this is not an issue for the <500mA case. I've used the MAX8819A charger in conjunction with an FTDI and I haven't had a bug report about it not charging.
But I see your point: that board doesn't have USB. Which is unfortunate...
I have always assumed that the Propeller needed to be reset prior to programming. Pardon my ignorance but is that a valid or invalid assumption? A reset jumper would have to be inside of the S3 and only be accessible after removing the screws and taking the product apart. If my assumption is true, then removing the jumper would create a non-programable robot requiring the user to take it back apart. This seems like a potentially bad user experience but maybe I'm missing something.
Thanks,
Ben
It looks like these 5mm pluggable screw jacks like this would fit if we used a right angle connector mounted on the bottom of the back PCB.
http://www.on-shore.com/sites/default/files/manuals/edz950.pdf
http://www.on-shore.com/sites/default/files/manuals/edstl950.pdf
The problem is someone might wire it backwards which would blow the charge control chip. A reverse biased diode could protect the charge chip input by tripping the battery internal PCM but that would add another ~50-100 uA of leakage current always draining the battery. Also if a user wired up a pack without a PCM by mistake, they would probably wind with a flaming Scribbler.
That leaves with either the XT60 on flying leads or something non-standard like a barrel jack or a rectangular connector like the old Tamiya NiMh packs used. If 1S cells aren't common in the RC world anyway, maybe it doesn't really matter.
There doesn't seem to be a clear winner here.
Ben
Here's the mating connector in the DVR.
With the connector plugged in.
There's some writing on the side of the connector. I'll get a better look at it and add it here later.
I'm going to want to track down a source of these connectors for my own use.
I saw a reverse polarity protection circuit which used a relay. It didn't cause any voltage or current loss if the power supply was properly connected. A reverse polarity condition resulted in the relay being tripped and an error LED lit.
I think the down side to the circuit was the component cost and I also think it took up a bit of board space. I liked the design since it didn't interfere with normal use.
I'm not sure if the relay would operate fast enough to prevent damage though. I'll see if I can find the webpage again.
"125VAC
8A
AWG16-26"
On the other side is:
"WANJIE
WJ15EDGK
3.50"
There are also some compliance logos on the side of the connector.
Just Kidding.
Note to self: Fahnestock doesn't fall within the realm of spellcheck.
Noted.
Though that might get you attention.
I wanted to send a little update on the S3 design progress. Im happy to say that I have released the Front and Back boards for prototype production last week. I have attached the Rev A PCB schematics.
My CAD package added a 3D rendering tool in the last release, I cant decide if its actually a useful feature or not. The parts are rendered as solid rectangles unless you model them for real in a 3D tool and link them. This is adequate for most items I guess but the switches on the back board for example wind up being a lot bigger than then they are in reality.
I should have the raw PCBs back in a few days so Ill be building and debugging them up over the next few weeks along with wrapping up the mechanical changes. I have the 3D modeling complete on the front half of the robot including adding the cutout for the hacker port and the XBee module but I need to roll my UI changes and finish the battery compartment changes for the LiPo pack.
On the battery connector, I decided to just put a pair of pads for soldering wires for an inline battery connector. Let me know if you have any feedback.
-Ben
I don't have a very strong opinion about this but I think having a mating connector for the battery shown in post #161 makes the most sense of the options mentioned. I'm pretty sure there are multiple options for on board mating connectors. I believe the connector can handle 5A. The battery shown in post #161 is made to deliver up to 16A at 8V.
The connector shown in Post 161 is known as a BEC type I believe. The issue is that these type connectors will only take a 22 AWG wire which is going to have quite a bit of voltage drop even with the short wires at 4 Amps. With the single 3.6V cell, we don't have much voltage margin to play with. The RC cars use multiple series cells to get around this problem which would have been great for our application but would have complicated charging from the lower USB voltage. The XT60 is overkill but I think will fit if I tuck it up in side of the body to the side of the Back PCB.
Maybe I'll order some BEC connectors and measure how much drop I get at 4 Amps. I certainly prefer the size of it.
-Ben
I find the world of connectors very confusing but I thought "BEC" was usually the abbreviation for Battery Elimination Circuit. Many electronic speed controllers will include a BEC so the receiver can be powered with the same battery used to power the motor. I'm sure many BECs used that type of connector but I'd be surprised (though not very) if the connector itself is called a BEC connector.
Here's a couple of links to mating connectors.
http://www.hobbyking.com/hobbyking/store/__9683__Female_JST_battery_pigtail_12cm_length_10pcs_bag_.html
http://www.hobbyking.com/hobbyking/store/__9630__JST_Male_2_pin_connector_set_10pcs_set_.html
They're using the plastic housing to define the gender of the connectors. The metal part of the connectors will have the opposite gender.
I didn't see any PCB mountable connectors for these but I'd be very surprised if they didn't exist.