When it comes to finding the best budget-friendly flight controller (FC) and electronic speed controller (ESC) stack for FPV drones, the SpeedyBee F405 V4 and the iFlight BLITZ ATF435 are top contenders. Both offer excellent performance at a great price, but which one stands out as the best option? Let’s dive into the details and find out.
New to FPV? Check out our comprehensive flight controller buyer’s guide: https://oscarliang.com/flight-controller/
Table of Contents
Where to Buy
Get the SpeedyBee F405 V4 here:
- AliExpress: https://s.click.aliexpress.com/e/_DFU9NkF
- RDQ: https://oscarliang.com/product-6ro8
- GetFPV: https://oscarliang.com/product-bc57
- Amazon: https://amzn.to/46EzYZi
- FPV24: https://oscarliang.com/product-nqbg
- Speedybee: https://oscarliang.com/product-wncw
Get the iFlight BLITZ ATF435 here:
Differences and Similarities Between These Stacks
The iFlight BLITZ ATF435 is $9 cheaper than the SpeedyBee F405 V4, but price alone doesn’t tell the whole story. Let’s compare the two to see which stack offers the best value for your money.
For a deeper dive into the SpeedyBee F405 V4, check out my full review: https://oscarliang.com/speedybee-f405-v4/
Flight Controller
Processor and Sensors
The iFlight BLITZ ATF435 uses the AT32 chip, which helps keep costs down. Learn more about AT32: https://oscarliang.com/at32-flight-controllers/.
The AT32F435 MCU offers performance close to the STM32F722 at a much lower price. While the AT32F435 supports 8K looptime and DShot600, and the SpeedyBee F405 supports 4K looptime and DShot300, the difference in real-world flight performance is minimal.
Both stacks use the ICM42688 Gyro, so they are comparable in terms of noise performance and ease of tuning.
Both stacks feature built-in barometers and support i2c connections (SDA and SCL) for a compass, And they are both compatible with Betaflight and iNav firmware.
Features and Specs
Both stacks offer 6 UARTs, more than enough for most FPV pilots. Typically, you’ll only need 2 to 4 UARTs for peripherals like a radio receiver, GPS, digital VTX OSD, and SmartAudio (and ESC telemetry and camera control but these are rarely used nowadays).
The BLITZ FC features an onboard 32MB memory chip for Blackbox logging, offering around 20 minutes of flight data. In contrast, the SpeedyBee uses a micro SD card slot for Blackbox, which requires an micro SD card that would cost another $10.
The SpeedyBee F405 V4 has 8 motor outputs, while the iFlight BLITZ has only 4. This gives the SpeedyBee more versatility for complex builds like hexacopters or octocopters.
The SpeedyBee also has a built-in Bluetooth module, allowing you to wirelessly configure Betaflight settings via the SpeedyBee App on your phone—a feature not available on the BLITZ. You can however use an OTG cable to connect to your Android phone.
Solder Pads and Connectors
One of the standout features of the BLITZ is the size and spacing of the solder pads. They’re large with plenty of separations, making soldering a breeze even for beginners. The silkscreen labels are clear, and the layout is intuitive, with pads organized in two rows on each edge. The SpeedyBee pads are slightly smaller and closer together but still relatively easy to work with.
Most FC only has one single LED pad, but the Speedybee has LED strip pads at each corner, making LED light connection super easy.
On the BLITZ FC, there are some JST connectors on the bottom of the board for various peripherals like receiver, GPS and LED/Buzzer etc. However, the board lacks a standard connector for digital VTXs, requiring either a split connector or direct soldering. On the other hand, the Speedybee offers a standard connector for digital VTX such as the DJI O3, but for all other devices you’d have to direct solder. Both stacks have onboard AT7456E chip, and they support analog FPV system.
BEC
Both flight controllers include two voltage regulators (BEC): 5V and 9V. The Blitz offers 5V at up to 2.5A and 9V at 2A. The 5V output is more than sufficient to power various devices, including an ExpressLRS receiver and a few LED strips. The 9V regulator should handle most VTXs, though the DJI O3 Air Unit, which can draw up to 16W (1.8A at 9V), is close to the limit. In such cases, powering the VTX directly from the battery might be a better option. The 5V and 9V BECs in the Speedybee have a higher rating at 3A each, making them more reliable and capable of supporting more power-hungry devices.
4in1 ESC
Both brands use a 55A BLHeli_S ESC in their stacks. Performance and features are similar, with both being compatible with Bluejay firmware and equipped with onboard current sensors.
Despite having a similar current rating, the Speedybee 4in1 ESC includes a heatsink for cooling and protection. However, this adds about 10 grams of weight, which may not be a significant issue for typical 5″ FPV freestyle and racing drones, but could be a consideration if you’re building an ultralight drone where saving weight is crucial.
Another notable difference is the input voltage: the Speedybee supports 3S to 6S, while the Blitz supports 2S to 6S. For most users running 4S or 6S setups, both stacks will work perfectly fine.
The BLITZ ESC features tabs at each corner for soldering motor wires, which can make for a tidier setup, though it might be challenging to fit the ESC into some tight frames.
Which Stack Should You Get?
Both stacks will serve most people well if you’re building a typical FPV drone—whether it’s a 5″ or 7″ quadcopter running on a 4S or 6S LiPo/Li-ion battery, which are the most common setups today for freestyle, racing, cinematic, or long-range applications. Your choice between these stacks may ultimately come down to brand preference and price differences.
However, certain scenarios may call for choosing one stack over the other:
Who Should Choose the iFlight BLITZ ATF435:
- If you’re looking for the cheapest possible FC/ESC stack, the iFlight BLITZ ATF435 is $9 cheaper, and you won’t need to spend extra on an SD card for Blackbox logging.
- If you’re aiming for the lightest possible build, the Blitz stack is about 10g lighter than the Speedybee F405 V4.
- If you plan to power your quad with a 2S LiPo battery.
- If you prefer a solderless setup, the JST connectors on the bottom of the Blitz stack can be very helpful.
Get the iFlight BLITZ ATF435 here:
Who Should Choose the Speedybee F405 V4:
- If you are a beginner, Speedybee offers much better documentations and wiring diagrams. Also it has a much larger user base so you are more likely to get help from someone who have used this stack.
- If you need more versatility and flexibility in your setup.
- The 8 motor outputs allow for hexacopter and octocopter configurations.
- If you want to connect servos for head tracking, the extra motor outputs can be very useful.
- If you plan to install LED light strips on each arm, the Speedybee’s LED and 5V pads at each corner make wiring easier, and the 5V 3A BEC can support more LEDs.
- The built-in Bluetooth allows for wireless Betaflight configuration via your phone.
Get the Speedybee F405 V4 here:
- AliExpress: https://s.click.aliexpress.com/e/_DFU9NkF
- RDQ: https://oscarliang.com/product-6ro8
- GetFPV: https://oscarliang.com/product-bc57
- Amazon: https://amzn.to/46EzYZi
- FPV24: https://oscarliang.com/product-nqbg
- Speedybee: https://oscarliang.com/product-wncw
How About Flywoo F722 V2 and GEPRC Taker Stacks?
Flywoo and GEPRC also offer budget FC/ESC stacks, and while they have their pros and cons, I personally think Speedybee and BLITZ have an edge over them.
For instance, the Flywoo stack is $15 more expensive than the Speedybee, but it features the good old MPU6000 gyro, which may be a compelling selling point for some. However, the JST connectors and solder pads make it harder to build and repair, which puts me off. Otherwise, it’s a decent stack. For more details, check out my review: https://oscarliang.com/flywoo-goku-f722-v2-fc-stack/
The GEPRC Taker stack is similarly priced to the Speedybee, but its small solder pad and connector location impact the user experience. It also lacks various features that the Speedybee F405 V4 offers. See my review for more info: https://oscarliang.com/geprc-taker-f405/
Conclusion
Both the SpeedyBee F405 V4 and the iFlight BLITZ ATF435 are excellent choices for budget FPV builds, each with its strengths. Your decision should be based on your specific needs and preferences, whether you prioritize cost, weight, or versatility. Either way, you’re getting a quality stack that delivers great performance without breaking the bank.
14 comments
I have the Blitz ATF435 in a Nazgul Eco BNF. Recently I broke the Blitz M10 GPS it came with.
I looked at your GPS recommendations and would like to replace it with the Flywoo M10 Pro (which is half the price of the Blitz M10 V3, here in Germany at least). Problem is that the flywoo comes with bare wires and I can’t solder to the FC because of the plug. Also it looks like the flywoo is using a different JST connector on the GPS, so I can’t reuse the cable from my Blitz GPS (I think?).
What would you do in my situation?
Usually the JST connectors on the FC are broken out to solder pads, find out what UART they are using for GPS, and solder the GPS directly to the solder pads?
Failing that, cut the connector off the cable from the FC, and solder that directly to the GPS?
I didn’t know that the connectors had broken out solder pads, that’s great to know for the future! That would have been the solution.
I ended up ordering the HGLRC M100-5883 because it seems to have the same connector and therefore should be a plug and play solution, hopefully. 🤞
Hello! I read from iflight website that ATF435 FC is plug and play with dji digital vtx. You said on this review that ATF435 lacks a standard connector for digital VTXs. Have they updated it or which information is wrong? :)
Just look at the wiring diagram – like i said it works but you need to split the cable.
Hi,
what’s your opinion on HAKRC F7220 V2 stack (aliexpress.com/item/1005005825316365.html)? It supports both inav and betaflight.
There’s also an F405 version – aliexpress.com/item/1005005821769121.html
One more note: could you please fix the website so that it does not switch to dark mode after loading? Or at least save the state in a cookie :)
There’s also the aspect of ESC which was not discussed here, in that iFried an absolute non-starter. There is a F405 8s budget stack by Foxeer which should be the contender for best value currently.
Also 8k loops don’t matter in f405 unless dshoot600 is in play and there are no other peripherals like Gps.
agree
and iFlight have both 8k loop AND dshot 600 enabled out of the box and factory ‘tune’ settings that are in the warning zone in betaflight as being aggressive and can cause fly-aways and instability…
I might just burn down the ‘factory tune’ and start over with a 4k loop and dshot 300 which is absolutely fine for a freestyle 5″ and tune it right
its absolutely the ESC that is at fault I believe with the current measurement issues in this f435 stack as that is where the current ADC resistor would be taking the measurements so unless the firmware on the esc processor is incorrect and giving bad values to the current data being collected and betaflight has to sort it out on the FC.. still TBD.. just deciding if its worth my while breaking it down on the bench and getting the test tools out to see where iflight have screwed up and fix their issues
I have a F435 from iFlight on a pre-build BNF.. and I am not impressed
It has LOTS of video noise that I have tracked back to noise in the flight controller as video passes though it to the VTX and OSD
Second and more distruturbing.. in Betalight during the iFlight ‘Factory Tune’ process.. they had to have a current offset of -19000 …. THATS HUGE.. every other FC I have has generally been ZERO.. only having to have a small adjustment to other variables …
Why would a FC need that kind of offset.. only thing I can think of is very poorly designed VR
What kind of build do you have? Did you connect a capacitor at the ESC power?
its an iFlgiht Nazgul ECO, built by iFlight and tuned by them.
the FC comes with a SMD capacitor as standard… the generic iFlgiht betaflight file for the ECO shows no offset but mine clearly needs it.. if reset to zero it will show 1300mah consumed within moments of starting flight
Interestingly, I’m just having the exact same problem. Related to the current meter setting of -19000.
I contacted iFlight and they say defaults are “0” for current offset.
Is seems like a wrong value component was put in or a faulty batch. And using -19000 as a band-aid. Which iFlight deny there is any problem.
It is nicely built, ( been flying for 10 years ) and never any of my quads needed anything but 0.
It’s not a polished product, with a current meter out so much, especially after the cheeky $20 price increase, . Tuned out the box as delivered which they deny -19000 was set.
I assume you got the v1.1 with solid XT60 mount?
negative.. my xt60 is not the hard mount.. its the earlier version..
iflight is crap..
first.. I bought this as a ‘no reciever’ BNF.. but they did not include the FC to RX cables that would normally come if you just bought the FC.. or that iflight generally include … worse.. it that the 4 wire connector they used in the 6 pin header for the receiver UART was pinned out to the non inverted pin.. so any SBUS receiver could not be wired and that connector was glued in.. its amateur hour.. and after spending 200 on this drone.. they wanted me to go out and find and buy the cable.. rediculous ..
I agree.. this batch of cheap F4 flight controllers have a defect either in design and / or manufacture… and you can talk to iflight til your blue in the face and they are too dumb to understand what your talking about.. and don’t care about the customer…
first and last iflight product.. its a junk company being pushed by influencers .. way better value for money out there.. even my arris hobby cheap quad from years ago light years better than this iflight garbage..
if it was just an annoyance with current measurement it would be less a factor but there is so much noise in the system I think it effects the drones overall performance .. motors are warm.. video noise.. just crap…
I bought iFlight BLITZ Mini ATF435 Stack and I have the same issue with the current sensor. There is an offset proportional to battery voltage. If I set the offset to be average of battery voltage over time, it shows somewhat useful numbers, but this is not an accurate way to measure it. Also I found somebody on Github complaining about the same issue. I’m not sure if this is a design flaw or manufacturing defect.